I was going to guess 4 years ago but this
seems to suggest 5 years. Balancing threads tended to turn hot back then. I seem to recall one thread giving a link to shops with the Snap-on static balancer equipment -- they weren't that common. Faulty memory or not -- more recently I've read "free information" here (get what you pay for?) that the only shop known to readers of that thread (not a large sample probably) with that equipment any more is Inland.