Year Percent 1950 14.02898 1955 14.98562 1960 16.06577 1965 17.30831 1970 18.44415 1975 19.53037 1980 20.09964 1985 20.64524 1990 25.32941 1995 24.60254 2000 24.61899 2005 25.52901 2010 26.67803 2015 26.80911 2020 27.32223 2025 28.19056 2030 29.42618 2035 30.21962 2040 30.365 2045 30.55668 2050 31.34446 2055 32.50421 2060 32.23143 2065 32.20225 2070 32.65704 2075 33.15904 2080 33.78074 2085 34.35797 2090 34.78709 2095 35.19727 2100 35.72885