Year Percent 1950 16.19367 1955 16.09936 1960 15.18302 1965 14.82868 1970 14.54592 1975 14.58316 1980 15.27646 1985 15.81631 1990 16.29189 1995 18.13114 2000 19.88424 2005 23.31973 2010 26.18478 2015 28.20993 2020 27.39108 2025 26.58822 2030 25.36494 2035 25.06228 2040 26.36045 2045 25.55571 2050 24.73619 2055 23.90541 2060 21.43308 2065 21.148 2070 22.2004 2075 22.21744 2080 21.77476 2085 21.01927 2090 20.45446 2095 20.4134 2100 20.76594