Please check my code and comment

Write a program that calls a method RollDie that simulates the rolling of a pair of dice 1000 times.  Use an array of size 11 to keep track of the rolls. After the 1000 rolls, output a list of the Rolls (2-12) and the frequency (count out of 1000) of each roll.  

#include <cstdlib>
#include <ctime>
using namespace std;
void RollDie(int counts[]) 
{
    for (int i = 0; i < 13; ++i)
    {
        counts[i] = 0;
    }
    for (int i = 0; i < 1000; ++i)
    {
        counts[(1 + rand() % 6) + (1 + rand() % 6)]++;
    }
}

int main()
{
    srand(time(NULL));
    int counts[13];
    RollDie(counts);
    cout << "Roll Time\tFrequency" << endl;
    for (int i = 2; i <= 12; ++i)
    {
        cout << i << "\t\t" << counts[i] << endl;
    }
    return 0;
}