Numbers missing: what is the typical valuation at Series A for a company coming out of YC? If it's $2 million then he'll wind up with (on average) 7.5% of each

Numbers missing: what is the typical valuation at Series A for a company coming out of YC? If it's $2 million then he'll wind up with (on average) 7.5% of each company (similar to what YC itself gets for about eight times less money), so to break even on one exit it'll have to be a $100+ million exit, which would be bigger than any YC exit so far as far as I know.