You're going too granular. This is about populations that live in certain areas, not specific people on specific days. "depends on where you are" when talking about an over-time risk ratio. The goal isn't to find some dude with weird habits.

And while a population that mostly stays inside a city has a reduced lightning chance, it also has a reduced shark chance. I don't think that's anywhere near the point of equalizing the rate.

If you have an idea for a factor that dramatically reduces lightning risk but doesn't reduce shark risk much, I'm interested.