How to round robin writing to an array

RoundRobin.cs

int length = 10;
var numbers = new int[length];

int r = 0;
for (int i = 0; i < 100000; i++)
{
    r = unchecked(r + 1);
    numbers[r % length] = r;
}

This could be useful for computing rolling averages, for example. If the something like a flow-rate is written into the array (instead of the sample value r above) then periodically, every time r % length == 9 perhaps, the code could tot-up the average.

Storing 1.0 or 0.0 floats for successes and failures could be used to take an average and compute a reliability for a circuit-breaker.

I think .NET integers are unchecked by default so this might work, too.

numbers[r++ % length] = value;