Year Percent 1950 9.97113 1955 9.16364 1960 8.46151 1965 9.43186 1970 10.81174 1975 12.11241 1980 12.44702 1985 11.76685 1990 11.19263 1995 10.70095 2000 11.01915 2005 10.56987 2010 10.71895 2015 10.68196 2020 10.01766 2025 8.81168 2030 8.47003 2035 8.39567 2040 8.15649 2045 7.72802 2050 7.25786 2055 6.87623 2060 6.61782 2065 6.43884 2070 6.26338 2075 6.08138 2080 5.89721 2085 5.74933 2090 5.64516 2095 5.56711 2100 5.50285