Fig. 3

Comparison of annual mean population-weighted UV radiation and MM incidence rate in 176 countries from 1990 to 2021. (A) Scatter plot of annual mean population-weighted UV radiation and MM incidence in 1990, with point size representing incidence numbers and color indicating SDI (Socio-Demographic Index), fitted with a GAM curve. (B) Scatter plot for 2021 with similar parameters and GAM fitting. (C) Temporal trends comparing annual GAM-fitted curves from 1990 to 2021, with solid lines for 1990, 2021 and 1990–2021, and dashed lines for other years.