Wins- 3 (Andretti- Sonoma '06, Iowa '11 & Carpenter- Kentucky '11)
Top-ten finishes- 155
Combined starts by all drivers who raced in Indycar- 601
Number of drivers who were a part of those 601 starts- 28
The 28 Drivers- Andretti, Antinucci, Battistini, Beatriz, Camara, Carpenter, Chesson, Clauson, Cunningham, Dana, Herb, Hildebrand, Hinchcliffe, Howard, Kimball, Lloyd, Luyendyk Jr., Mann, Matos, Medeiros, Mutoh, Newgarden, Perera, Plowman, Roth, Saavedra, Simmons, and Taylor.
So after further analysis, I am a bit surprised. I was fairly pessimistic in my thoughts before doing the research. But after looking at these numbers, I am surprised. That is a lot of top-ten finishes from Lights graduates. You take look at this while also realizing that a) A lot of the drivers were part time drivers b) The only drivers that were/are on the "big teams" were/are Marco Andretti, Hideki Mutoh, Charlie Kimball, and James Hinchcliffe. The others were on small teams or teams that fielded a part-time entry.
Let me know what you think.