I set every single egg my trio laid last year. They aren't poor layers, either. After two months, one of the hens finally started laying fertile eggs. Of that one hen, about 25--50% of the fertile eggs hatched. (I averaged 95--98% hatch rates the year prior on quail and mutt eggs.) Of those chicks, which numbered 10--15, exactly two of them lived to maturity. Thankfully, this year has been far better. The second hen started laying fertile eggs, and while I pulled a dismal ~50--75% hatch rate, I only lost one chick, which was to a freak accident. Swapping around the breeding pairs with some second generation birds helped, I think. I suspect hatchability will be a difficult issue to contend with, as it appears to be genetic and not environmental, unfortunately. I will keep trying out various crosses with the birds I now have and see if I can improve their overall quality in the next few years.
If I look back at my records, I could most likely find exact numbers.