Year Percent 1950 8.42255 1955 7.64028 1960 8.45649 1965 9.74246 1970 10.97819 1975 10.89858 1980 9.68323 1985 10.32378 1990 13.31514 1995 15.0139 2000 16.46207 2005 16.68638 2010 18.62408 2015 21.27398 2020 22.54927 2025 23.28032 2030 23.91985 2035 24.96958 2040 26.34069 2045 27.55053 2050 29.28388 2055 30.66239 2060 31.62055 2065 32.47431 2070 32.93054 2075 33.34281 2080 33.82356 2085 34.33483 2090 34.80394 2095 35.21123 2100 35.58303