Table:
text: Canadian Interuniversity Sport football
Teams
Ontario University Athletics 
 Yates Cup
Institution Team City Province First_season Head_coach Enrollment Football_stadium Capacity
University of Windsor Lancers Windsor ON 1968 Joe D`Amore 13496 South Campus Stadium 2000
University of Western Ontario Mustangs London ON 1929 Greg Marshall 30000 TD Waterhouse Stadium 10000
University of Waterloo Warriors Waterloo ON 1957 Joe Paopao 27978 Warrior Field 5200
Wilfrid Laurier University Golden Hawks Waterloo ON 1961 Michael Faulds 12394 University Stadium 6000
University of Guelph Gryphons Guelph ON 1950 Stu Lang 19408 Alumni Stadium 4100
McMaster University Marauders Hamilton ON 1901 Stefan Ptaszek 25688 Ron Joyce Stadium 6000
University of Toronto Varsity Blues Toronto ON 1877 Greg Gary 73185 Varsity Stadium 5000

Question: What is the average capacity of stadiums in the City of London belonging to schools with fewer than 30,000 enrollments for the Canadian inter-campus sports Football of Ontario Athletics Yates Cup teams?