I think it's just hard to estimate. How many visits-to-the-beach go into that shark attack number? It'd be useful to know the per-visit risk for the same reason

I think it's just hard to estimate. How many visits-to-the-beach go into that shark attack number? It'd be useful to know the per-visit risk for the same reason it'd be useful to know the per-mile risk for driving, but is harder to estimate: "It’s important to be aware, however, that being based on population-level data, the micromort is not a measure of your personal risk. For example, the risk calculation for fatal shark attacks is based on the average risk across the whole population. So it effectively estimates a risk based on the assumption that all Australians swim in the deep ocean a similar number of times per year. But if you live in Alice Springs, you would not expect your risk of being killed by a shark to be the same as for a surfer who lives on the coast. Similarly, if you only wade in water up to your knees and don’t swim in deep water, your personal risks would be different."