I almost always play 769-1453 unless something goes really wrong and I basically write off the playthrough. On average, each playthrough ends up around 100-120 hours I guess, if I do the math correctly? Something like that. I spend a lot of time paused checking the status of certain things around the world. Had a certain period when I first started the game where on several occasions, I played more than 100 hours per week. I extremely do not recommend doing that, by the way, though it had less direct consequences than the time 20ish years ago I literally lost an entire summer, from last day of school to first, to Civ II...
I tend to be a thorough and detail-oriented sort of person who has trouble letting things go, you could say. I think for someone less obsessive than me, 10 hours per century of play sounds like a decent rule of thumb.