Year Percent 1950 15.10212 1955 13.58158 1960 12.49026 1965 12.53509 1970 13.68873 1975 14.61109 1980 14.59502 1985 13.466 1990 12.20755 1995 13.40068 2000 15.71913 2005 18.65165 2010 20.89683 2015 21.63861 2020 22.13537 2025 23.19461 2030 24.36888 2035 25.43249 2040 25.49933 2045 24.89668 2050 24.46685 2055 24.61685 2060 25.10703 2065 25.36215 2070 25.21342 2075 24.3795 2080 23.73035 2085 23.37144 2090 23.22521 2095 23.10854 2100 22.87208