Paul.judging by what has been quoted on here , a 1% return you will get 4 jobs :

,
I think you willl find the true figure is more likely to be 0.1 % if its a really good flyer, and goes out as solo and the houses are selected , then this may rise slightly .
I only wish i could achieve 1% return , 10 jobs from 1,000 leaflets ,doubtful

Geoff