How use backgroundworker or processbar for load data from databse

my code :
List<models.listmali> List=null;
bool complete = true;
private void frmListMali_Load(object sender, EventArgs e)
{


backgroundWorker1.WorkerReportsProgress = true;
backgroundWorker1.RunWorkerAsync();

}
int tiem = 0;
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
loadData();
DateTime start = DateTime.Now;
for (int i = 0; i < 100; i++)
{
Thread.Sleep(100);
backgroundWorker1.ReportProgress(i);
}


}
private void loadData()
{
tiem += 100;
try
{
Models.NezamDBEntities _db = new Models.NezamDBEntities();
List = _db.ListMalis.ToList();

}
catch (Exception ex)
{

MessageBox.Show(ex.Message);
}

}
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
complete = false;
dgvListMali.DataSource = List;
progressBar1.Visible = false;

}

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
}

but not good