“(If you want my answer for the “average frum family” (ie excluding newcomers and excluding those who may be exceptionally learned) Id say range between twice a month and 4 times a year (other than taharas hamishpacha) Admittedly I have no idea how I came up with this number)”
That seems to me like a very low estimate. Not necessarily in terms of how many sheilas people ask, but at least in terms of how many sheilas they actually have and would want to ask (but may not have anyone to ask).
I think that the range amongst people I know is more like once every week to at least once a day.
But most people I know don’t end up asking each time, either because they don’t have “A Rav” to ask all their sheilas to, or there is no one to ask because it’s Shabbos and they need an immediate answer, or it’s difficult/impossible to find someone to ask each time a sheilah arises and it’s the kind of thing that they can just avoid doing if they have no one to ask.