Duplicate grid binds serverl times on a single page on scrolling down

<pre>SELECT T.DeptID As DeptID  ,SUM(CASE WHEN datepart(yyyy,T.DOJ) between 2005 and 2017 and T.Status =0 then 1 else 0 END) As TotalHeadCount, 
SUM(CASE when T.DOJ >= cast('2017-01-12' as datetime) and T.Status =0  then 1 else 0 END) As NewJoinees1, 
SUM (CASE When T.deactivate>= Cast('2017-01-12' as datetime) and T.Status =0 then 0 else 1 END) As Resigned1, 
SUM(CASE WHEN T1.Tobehired IS NULL THEN '0' ELSE Tobehired END) AS Tobehired ,
SUM(CASE WHEN  T1.Openposition IS NULL THEN '0' ELSE Openposition END)  As Openposition ,T1.Status As Status
FROM EmployeeDetails T  LEFT JOIN RecruitmentDetails1 T1 on T.DeptID = T1.DeptID
Where T.Status=0
GROUP BY T.DeptID
       , T1.Tobehired
       , T1.Openposition
       , T1.Status 

<pre><asp:View ID="View2" runat="server">

                                    <br />
                                    <br />
                                    <table align="center" class="table table-bordered">
                                        <tr valign="middle">
                                            <td>Month
                                            </td>
                                            <td>
                                                <asp:DropDownList ID="ddlMonths" runat="server"></asp:DropDownList>

                                                <%--<asp:TextBox ID="txtmonth" runat="server"></asp:TextBox>--%>
                                            </td>
                                            <td>Year
                                            </td>
                                            <td>
                                                <%--<asp:TextBox ID="txtyear" runat="server"></asp:TextBox>--%>
                                                <asp:DropDownList ID="ddlyear" runat="server"></asp:DropDownList>
                                            </td>
                                            <td>
                                                <asp:Button ID="btnGenerate" runat="server" CssClass="btn btn-wide btn-dark-grey" Text="Find" OnClick="btnGenerate_Click" />
                                            </td>
                                        </tr>
                                    </table>
                                    <table align="center">
                                        <tr>
                                            <td>
                                                <span id="printcontent1">
                                                    <asp:DataList ID="DataListHeadCount" HorizontalAlign="Center" DataSourceID="SqlDataSourceHeadCount" runat="server">
                                                        <ItemTemplate>
                                                            <table align="center" class="table table-bordered">
                                                                <tr align="center">
                                                                    <td>Data
                                                                    </td>
                                                                    <td>COUNT
                                                                    </td>
                                                                </tr>
                                                                <tr>
                                                                    <td>NEW JOINEES
                                                                    </td>
                                                                    <td align="center">
                                                                        
                                                                    </td>
                                                                </tr>
                                                                <tr>
                                                                    <td>RESIGNATIONS
                                                                    </td>
                                                                    <td align="center">
                                                                       
                                                                    </td>
                                                                </tr>
                                                                <tr>
                                                                    <td>TOTAL HEADCOUNT
                                                                    </td>
                                                                    <td align="center">
                                                                        
                                                                    </td>
                                                                </tr>
                                                            </table>
                                                            <div>
                                                            <table >
                                                                <tr>
                                                                    <td
                                                                        colspan="7" align="center">
                                                                        <%=ddlMonths.Text %><%=ddlyear.Text %></td>
                                                                </tr>
                                                               

                                                                <tr>
                                                                    <td>
                                                                        <asp:GridView ID="grdvEmployeeLeaveUpdate" runat="server" DataKeyNames="" 
                         class="table table-bordered table-striped table-hover" DataSourceID="SqlDataSourceHeadCount"   
                        OnRowDataBound="grdvEmployeeLeaveUpdate_RowDataBound"  AutoGenerateColumns="False" Width="100%"  
                        OnRowDeleting="grdvEmployeeLeaveUpdate_RowDeleting"
                        OnRowEditing="grdvEmployeeLeaveUpdate_RowEditing"
                        OnRowUpdating="grdvEmployeeLeaveUpdate_RowUpdating"
                        OnRowCancelingEdit="grdvEmployeeLeaveUpdate_RowCancelingEdit"
                         OnPageIndexChanging="grdvEmployeeLeaveUpdate_PageIndexChanging">
                        
                        <Columns>
                            <asp:BoundField DataField="DeptID"  HeaderText="Cost Center" ReadOnly="true"   />
                            <asp:BoundField DataField="TotalHeadCount" HeaderText="HeadCount" ReadOnly="true"    />
                            <asp:BoundField DataField="NewJoinees1" HeaderText="Additions" ReadOnly="true"   />
                            <asp:BoundField DataField="Resigned1" HeaderText="Separations" ReadOnly="true"   />
                            <asp:BoundField DataField="Tobehired" HeaderText="To Be Hired"  ControlStyle-Width="80px" />
                            <asp:BoundField DataField="Openposition" HeaderText="Open Position" ControlStyle-Width="80px" />
                            <asp:BoundField DataField="Status" HeaderText="Status"  ControlStyle-Width="80px" />
                            <asp:CommandField HeaderText="Update" ShowEditButton="True" ControlStyle-Width="80px" />
                            
                        </Columns>
                        <HeaderStyle></HeaderStyle>
                    </asp:GridView>

                                                                    </td>

                                                                </tr>

                  </table>
                                                                </div>
                                                            
                                                        </ItemTemplate>
                                                    </asp:DataList>
                                                </span>
                                            </td>
                                        </tr>
                                    </table>

                                    <table align="center">
                                        <tr valign="middle" align="center">
                                            <td align="center">
                                                <asp:Button ID="btnExport" runat="server" CssClass="btn btn-wide btn-dark-grey" Text="Export To Excel" OnClick="btnExport_Click" />
                                                <input id="Button2" class="btn btn-wide btn-dark-grey" onclick="return doprintcontent1();" type="button" value="Print Page" />
                                            </td>
                                        </tr>
                                    </table>
                                    <asp:SqlDataSource ID="SqlDataSourceHeadCount" runat="server" ConnectionString="<%$ ConnectionStrings:TimeSheetConnectionString2 %>"
                                        SelectCommandType="StoredProcedure" SelectCommand="Sampe4"
                                        UpdateCommand="UPDATE RecruitmentDetails1 SET Tobehired = @Tobehired, Openposition = @Openposition, Status=@Status WHERE DeptID = @DeptID">
                                        <SelectParameters>
                                            <asp:ControlParameter ControlID="ddlMonths" Name="months" Type="Int32" />
                                            <asp:ControlParameter ControlID="ddlyear" Name="years" Type="Int32" />
                                        </SelectParameters>
</asp:SqlDataSource>
</asp:View>