Year Percent 1950 19.68473 1955 18.88911 1960 17.95673 1965 16.12603 1970 14.20498 1975 12.93534 1980 12.11595 1985 11.73498 1990 11.01235 1995 11.68308 2000 11.64818 2005 12.10966 2010 13.60233 2015 14.40667 2020 15.59943 2025 16.42979 2030 16.82333 2035 17.18386 2040 17.62681 2045 18.03651 2050 18.61 2055 19.38321 2060 20.0522 2065 20.70923 2070 21.20662 2075 21.54481 2080 21.91728 2085 22.32041 2090 22.69941 2095 23.02332 2100 23.27329