I worked it out a few years ago...so this number is low now.
The number I got was around.... 22,800.
That doesn't include the last 5 years or so, which was ALL over the map; some weeks it was 20 hours, other's 0. ROUGH guess...maybe another 1,700 or so. I have REALLY slowed down in the last 5 years...age, health, family, life in general for everyone involved, etc. Back in my heyday when we were all 15? Hitting 700 to 1,000 hours was a good summer vacation (with time left to go on those dreaded "family camping trips"...ok...they weren't dreaded...they were pretty awesome...but I live in the Yukon, so, yeah... ).
EDIT: I'm talking about play time only. Adding in "prep, reading, drawing, etc" (re: doing all that "extra hobby stuff for fun")? OMG...don't even want to think about it! Twice that, easy!