If it is possible to compare with Europe (where I think skydiving is a smaller sport compared to USA?):
The last three years, the time I've been in the sport, there have opened tunnels in Czech Republic, Norway, Spain, Russia and a small one in Denmark.
Other than that there's three tunnels in the UK: Manchester, Milton Keynes, Bedford and a new one opening next summer in Basingstoke.
There are also a tunnel in Germany, and another one in Russia.
I believe there's also one being opened in France next year.
There might be small tunnels and others that I don't know of.