200 180 mortality(per10 000 160 140 120 100 80 60 20 ◆◆,今 0 1900191019201930194019501960197019801990 Mortality Trends with Pneumonia from 1900 to 1990 in USA 2021/2/23 Dr HU Bijie Semin respir Infect 9(3): 140-52, 19942021/2/23 Dr.HU Bijie 3 Semin Respir Infect 9(3):140-52，1994 mortality (per10 000) Mortality Trends with Pneumonia from 1900 to 1990 in USA 0 20 40 60 80 100 120 140 160 180 200 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990