Year Percent 1950 12.90977 1955 12.77702 1960 13.93996 1965 13.85732 1970 13.71895 1975 13.47616 1980 13.36337 1985 13.01465 1990 12.43846 1995 11.30188 2000 10.34352 2005 10.03309 2010 9.3031 2015 8.77186 2020 8.42553 2025 7.63465 2030 7.18532 2035 6.70603 2040 6.36199 2045 6.06439 2050 5.8256 2055 5.59726 2060 5.38326 2065 5.20347 2070 5.08065 2075 4.99229 2080 4.93816 2085 4.88075 2090 4.82675 2095 4.77573 2100 4.74163