I think I have seen such data before, at least about how many of them were still businesses out of the total number of funded companies.
(Btw is it Firefox or Hacker news that is correcting spelling?)
There are 22 in the summer cycle, so the total funded is 102,
representing roughly 250 founders.
What do you mean by "review"? TechCrunch "reviews" many of the YCombinator funded startups when they first launch, so you could search there. I remember seeing a large list of the companies and their "status" (e.g. acquired, funded, etc). However, http://en.wikipedia.org/wiki/Y_Combinator is the only list I can find at the moment which isn't very comprehensive.
You have to give non-native speakers a break. I know I sound significantly dumber than I am in French and Spanish.
I am swedish btw.
In any event, I'll offer you three hints that may help you reach fluency. First, you are less likely to make errors and more likely to be understood if you use simple sentience structures. Second, never use the word such. Third, always capitalize American.
Anyway I ment measuring the success. How many are actually making money(I mena not just having revenue but revenue > expenses).