Here is further explanation. It looks like Wuhan has a much higher fatality rate than everywhere else. So, if you combine both Wuhan & elsewhere, the numbers look bad.
https://www.worldometers.info/coronavirus/coronavirus-death-rate/
Worth noting
“ Elderly people with basic diseases, as long as they have pneumonia, were clinically a high-risk factor regardless of whether it is a coronavirus or not, and the case fatality rate was also very high, so it is not that the case fatality rate of pneumonia is high because of the infection with the new coronavirus. “This point must be explained to everyone,” concluded the NHC official.[7]”