Year Percent 1950 19.55174 1955 19.09755 1960 18.15468 1965 18.97458 1970 19.56193 1975 21.16746 1980 22.21475 1985 21.64801 1990 24.40325 1995 26.22895 2000 27.89486 2005 29.1177 2010 27.17767 2015 26.16015 2020 25.75265 2025 26.23726 2030 27.82529 2035 28.65684 2040 27.90196 2045 26.05808 2050 24.01353 2055 22.51188 2060 22.10676 2065 22.63381 2070 23.08672 2075 22.98095 2080 22.55056 2085 22.04197 2090 21.80295 2095 21.92954 2100 22.19172