Year Percent 1950 20.01906 1955 18.86738 1960 19.03703 1965 19.74664 1970 17.87623 1975 14.55494 1980 14.26989 1985 15.26082 1990 14.08994 1995 14.12215 2000 13.53969 2005 13.6123 2010 13.20568 2015 12.16107 2020 11.0918 2025 10.84781 2030 10.89505 2035 10.78944 2040 10.35283 2045 9.61822 2050 8.88541 2055 8.42676 2060 8.267 2065 8.13635 2070 7.84049 2075 7.37436 2080 6.88375 2085 6.51232 2090 6.31638 2095 6.20181 2100 6.0539