Year Percent 1950 12.50839 1955 13.45012 1960 14.68995 1965 15.71548 1970 16.85179 1975 17.71914 1980 18.09453 1985 18.53353 1990 22.98926 1995 22.34052 2000 22.08927 2005 23.19939 2010 24.98162 2015 26.27555 2020 27.63392 2025 29.2132 2030 30.77218 2035 31.40509 2040 31.58197 2045 31.06964 2050 31.13285 2055 32.01681 2060 32.61225 2065 32.99548 2070 33.54877 2075 33.69619 2080 34.04649 2085 34.60539 2090 35.18748 2095 35.68661 2100 36.12315