Fig. 4. Shifting age and sex distributions through time.

(a) Age and sex distributions of confirmed cases with known travel history to Wuhan. (b) Age and sex distributions of confirmed cases that had no travel history. (c) Median age for cases reported early (before 1^st Feb) and those reported later (between 1^st – 10^th February. Full distributions are shown in fig. S7. (d) Change through time in the sex ratio of (i) all reported cases in China with no reported travel history, (ii) cases reported in Beijing without travel history, and (iii) cases known to have travelled from Wuhan.