Figure 4.

Boxplots of daily minimum exposure durations (in hours) needed to receive one MED (t_{MED, min}) for skin types I–VI for days with rounded UVI values of 2. Bold line: median, lower/upper edge of box: 25%/75% quantile (first/third quartile), whiskers: range of data points which are no more than 1.5 times the interquartile range out of the box, dots: outliers. N (%) denotes the absolute (relative) number of observations in the subsample, i.e., the absolute (relative) number of UVI 2 days for which one MED could actually be received. The trend in t_MED,min with respect to skin type can be considered significant (p < 0.001).