Year Percent 1950 10.71103 1955 11.44108 1960 12.27335 1965 13.11363 1970 13.90977 1975 14.51513 1980 14.93986 1985 15.7094 1990 19.78036 1995 20.20646 2000 20.47141 2005 21.1838 2010 23.6283 2015 25.62016 2020 27.8588 2025 30.36013 2030 32.68284 2035 34.03668 2040 34.35928 2045 34.58299 2050 35.02746 2055 35.44715 2060 35.65473 2065 36.0478 2070 36.26815 2075 36.43115 2080 36.74472 2085 37.14446 2090 37.55215 2095 37.93664 2100 38.26569