I think our club has about 75 dues paying members. Our monthly shoot (Sunday) draws about 25 shooters. Every 3 months, we also have a Saturday fun shoot - metallic silhouettes & BP shotgun which of late has 10 to 15 shooters. Our club is a bit odd in that few of the members live within 50 miles of the range, so if anybody wants to shoot Sat & Sunday both, they either camp on site or motel it at the local "Baghdad Bob's Motel". Sunday being the 'normal' shoot (club business meeting, dinner, and target shoot), it gets the larger attendance.
Another measure of how well your club is doing is how often you have folks apply as new members.
SCL