Year Percent 1950 10.22858 1955 9.24766 1960 8.43669 1965 8.49831 1970 8.64906 1975 8.91479 1980 8.84861 1985 9.17604 1990 10.94977 1995 11.38547 2000 12.175 2005 10.95122 2010 11.80245 2015 13.61079 2020 16.19929 2025 19.89123 2030 23.43221 2035 26.63768 2040 29.46508 2045 31.64802 2050 32.49435 2055 32.51085 2060 31.80253 2065 31.15348 2070 31.51088 2075 33.0212 2080 34.2717 2085 35.00175 2090 35.55365 2095 36.2102 2100 37.00421