Year Percent 1950 8.5762 1955 9.18884 1960 9.08242 1965 9.72943 1970 12.76692 1975 12.48068 1980 12.22901 1985 12.60682 1990 14.97054 1995 15.25941 2000 15.45495 2005 16.37864 2010 17.29556 2015 18.99228 2020 21.21505 2025 23.45955 2030 25.80688 2035 27.97203 2040 30.45054 2045 32.87268 2050 34.85849 2055 36.48582 2060 37.71789 2065 38.57235 2070 39.37034 2075 39.8613 2080 40.10595 2085 40.0897 2090 40.03345 2095 40.0482 2100 40.16619