I get very few from road hazards. My first year I got one from a staple, one from a sliver of glass. The 2nd year, one from a bit of wire, another from a sharp metal shard. I think that's it from road hazards. So it's been about 3 years since that kind of flat.
However, in ONE DAY I got 5 flats - because I had a bad rim strip in a new wheel. I had a valve stem blow out on me once. I had a tire rip loose from its bead last fall. I got a pinch flat this spring when I let a tire get low and I came across some really course gravel that I hadn't known was there. I had a patch fail on me once (got old and cracked). One time I wore a tire clear through, the tube poked out and popped.
Typically I get a flat about once a year, though as you can see recently it's not been for typical reasons. I just switched to brand new Schwalbe Marathons and I now have high quality rim strips and new wheels front and back, so it's possible I'm set for a while.
I only have one bike. Total miles is about 17400.
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Work: the 8 hours that separates bike rides.