|I left skating three times because of serious injuries. Once for two years, once for a year, and lastly for about 5 months. I have also taken bits of time off from smaller injuries, like swelling, etc..
During my years of vert skating, I have had some dry spells due to the lack of a skate park near me. I've gone at least months not skating, if not a year before, because of not having a skate ramp.
Roughly, I'd say that I have skated about 16 of the last 21 years.