Hmm, good question. At least a decade; I definitely remember going in 1996 and 1997, but I'm not sure about before that. (I think my first year was the first or second year it was in Goodale Park.)

Since then I've missed a few because Pagan Spirit Gathering usually overlaps with Comfest weekend, and both events are "home away from home" for me in different ways. This year I decided to skip PSG because I was sick of missing Comfest.