I think it's very much a matter of personal choice.
Of course, there are kids who are attending at least one or two or even more (!!!!!) every day, while some have a few for the whole week. Other than SC, I think it's the same for the other "popular" kgs.
Maybe it's more important to find out what suits the kid the best and how to pave the way well for him/her to prepare for P.1.