In 1998-99, there were 63 non AHL minor league hockey teams (IHL-16, ECHL-27,CHL-11, UHL-9.) This year, there are 36 (ECHL-28, SPHL-8). ***The FHL doesn't count
*** That's a decrease of 43% in 16 years. Probably safe to assume that making a buck in the minors is very difficult. Also safe to assume that most franchises aren't rich men's toys nor worthwhile tax write offs or the numbers wouldn't have precipitously dropped to the levels which they have in such a short time.
The AHL has grown from 19 to 30 in that time, but the evolution of the development system to a one AHL team for each NHL team is responsible for that-along with the demise of the IHL which had teams serve as the #1 affiliate for a few NHL organIzations. More and more AHL teams are becoming owned by their NHL parent clubs and when an NHL team owns its AHL affiliate, it is usually willing to absorb fairly substantial losses in operating these franchises as part of their player development costs.
I would expect non AHL minor league teams to continue to contract as time goes on. I don't see the ECHL having more than 20 teams (from its current 28) by 2020. Would love to be very wrong about this.