Table:
text: 1973 Canadian Grand Prix
Classification
Classification
Driver Constructor_ Laps Time_Retired Grid
Jody Scheckter McLaren - Ford 32 Collision 3
François Cevert Tyrrell - Ford 32 Collision 6
Mike Beuttler March - Ford 20 Engine 21
Ronnie Peterson Lotus - Ford 16 Suspension 1
Peter Gethin BRM 5 Oil Pump 25

Question: What is the average lap count in the 1973 Canadian Grand Prix when driver Peter Gethin has fewer than 25 on the grid?