Year Percent 1950 11.43485 1955 12.52854 1960 13.47128 1965 14.15609 1970 14.83005 1975 15.18982 1980 15.58104 1985 16.44906 1990 17.2269 1995 18.74266 2000 20.74629 2005 23.26044 2010 24.27874 2015 24.51282 2020 23.78043 2025 22.38263 2030 21.99725 2035 22.58745 2040 23.94796 2045 25.18155 2050 25.38373 2055 24.90544 2060 24.32602 2065 23.95649 2070 23.96249 2075 23.93163 2080 23.67462 2085 23.19499 2090 22.69661 2095 22.35049 2100 22.16966