With all due respect, I still don't think this is a workable "general" solution applicable to all (or even most) parks. Parks differ with respect to their long term or seasonal sites. Some have specific sites designated for long term residents, some do not. The park on Prince Edward island where we spent this past summer had a specific number of "seasonal sites" at a reduced rate and there was a long waiting list to get one of those. So your approach of total vs available sites would work there, assuming the owner wanted to publicize the fact. However, at the park where we spend the winter there are no restrictions on how many of the sites can be rented to monthly or seasonal folks like ourselves. The owners would be happy if all the sites were rented on a long term basis. Furthermore, in the summer, very few of the sites are rented for more than a week at a time. I'm not at all sure how a park like this could attempt to comply with your "total vs available" request.
