Year Percent 1950 15.09116 1955 15.9846 1960 16.77891 1965 17.28795 1970 17.73932 1975 18.28808 1980 18.56847 1985 18.6397 1990 17.91367 1995 17.08673 2000 17.42045 2005 17.53724 2010 16.80771 2015 15.86549 2020 15.17821 2025 14.58083 2030 14.0083 2035 13.38424 2040 12.73969 2045 12.08451 2050 11.47475 2055 10.91909 2060 10.393 2065 9.91248 2070 9.43515 2075 8.97463 2080 8.54394 2085 8.13609 2090 7.76136 2095 7.40171 2100 7.07489