15 ain't 30 plus.
http://www.powri.com/schedule-detail.asp?RaceID=24879
Eleven times during the 2015 season POWRi had car counts lower than 30. The high car count of the year was 69, the lowest was 13 cars. 5 times during the season they had car counts over 50. The Kunz cars won quite few races in POWRi also.
USAC had a high car of 53 and the lowest was 20 during the 2015 season.Eight times USAC had car counts over 30. Several races during the season [both clubs] were co-sanctions.