successful flush? looking for info from experienced flushers

Hi,
I've done 2 flushes so far, and in each one I got some stones.. first one 100 stones, pea sized, second flush five 20 mm stones and 40 or 50 tiny ones. All told the stones from both flushes fit into a 1/4 cup measurement.

I see pictures of sucessful flushes and it seems like people get 2 cups worth per flush. I do realize that the flushes are successful in that stones come out, but i have the feeling that I'm way under what I should be in output, and that i'll be doing 600 flushes before I'm stone free at this rate. As far as 'cups worth' of stones, or number of stones in a successful flush, what do you consider to be within the average sucessful range?



Thx
LisaG