In the U.S. in 1900 this was 46.3 for males & 48.3 for females; in 2000 it was 74.3 & 79.7
According to the U.S. Census Bureau, 35.1 million (
12.4%) of the U.S. population were aged ... 1900b,c, 47.3, 46.3, 48.3, 47.6, 46.6, 
48.7, 33.0, 32.5, 33.5 ... 2000, 77.0, 74.3, 79.7, 77.6, 74.9, 80.1, 71.9, 68.3, 75.2.