Year Percent 1950 9.51555 1955 8.1834 1960 6.75676 1965 5.82045 1970 5.46054 1975 5.43719 1980 4.96821 1985 4.91487 1990 6.80642 1995 7.49281 2000 8.67598 2005 7.74262 2010 7.68088 2015 8.34894 2020 9.30333 2025 10.8528 2030 11.47644 2035 12.19482 2040 12.78595 2045 13.64136 2050 15.33745 2055 16.34103 2060 16.05076 2065 15.83155 2070 17.34579 2075 20.05238 2080 22.03835 2085 23.37538 2090 24.29148 2095 25.13977 2100 26.16151