Mortality rate in deaths per thousand terawatt hour[1]:

  - Brown coal:  32.72
  - Coal:        24.62
  - Oil:         18.43
  - Biomass:      4.63
  - Natural gas:  2.82
  - Hydro:        1.30
  - Wind:         0.04
  - Nuclear:      0.03
  - Solar:        0.02

Again, these are adjusted per 1000TWh, and includes nuclear catastrophes like Chernobyl and Fukushima

1: https://www.statista.com/statistics/494425/death-rate-worldw...