Do most U.S. rinks beong to USIRA?

[Query]

I recently saw a copy of Rink magazine, put out by the U.S. Ice Rink Association

  http://www.usicerinks.com

which says it is a joint venture of the USFS[A] and USA Hockey.

Do most U.S. rinks belong to it, or is it mostly just a professional organization for some rink managers? Are rinks running USFSA and/or USA Hockey programs required to join? Do most ISI affiliated rinks belong?

The magazine deals with rink management, rather than teaching skating, or providing equipment to individual skaters. For example, there are ads for rental ice skates and supplies and equipment to maintain the ice.

They run an annual conference, NARCE (North American Rink Conference & Expo) which includes classes and trade shows.