In the 70s we had 3 squadrons with a nominal 8 crews each. The plan was to increase it to 9 crews per sqn to cope with the oil surveillance task, but we always struggled to maintain the 8 crews by juggling people around. I think we could probably have just managed 22 crews between the 3 sqns then.
I'm surprised nobody has mentioned 201's claim to be the oldest sqn having formed from the old 1 RNAS Sqn.