Year Percent 1950 10.78076 1955 11.35993 1960 11.94765 1965 12.92812 1970 13.68122 1975 14.36713 1980 14.81836 1985 15.80714 1990 20.96515 1995 23.05402 2000 23.88155 2005 24.05924 2010 24.93257 2015 26.81396 2020 29.30182 2025 32.39056 2030 35.61469 2035 39.19736 2040 42.49178 2045 43.99099 2050 44.17408 2055 43.81129 2060 43.08045 2065 42.77008 2070 42.92146 2075 42.65564 2080 42.3884 2085 42.2594 2090 42.31771 2095 42.55792 2100 42.92359