Year Percent 1950 9.73723 1955 9.29797 1960 8.64306 1965 8.70708 1970 9.07181 1975 9.28871 1980 8.42459 1985 8.78739 1990 12.06234 1995 13.30019 2000 14.57619 2005 13.80852 2010 14.23721 2015 15.39862 2020 17.51697 2025 19.24002 2030 19.92134 2035 20.76573 2040 21.89454 2045 23.77795 2050 25.93966 2055 26.65525 2060 26.00999 2065 25.36353 2070 25.61922 2075 26.69841 2080 27.66586 2085 28.36945 2090 28.69456 2095 28.8662 2100 29.22277