Year Percent 1950 11.74006 1955 11.41953 1960 12.82245 1965 13.47276 1970 14.09493 1975 14.65344 1980 14.92265 1985 15.25487 1990 15.40709 1995 15.25202 2000 15.2534 2005 14.96177 2010 14.69896 2015 14.50161 2020 14.14482 2025 13.63258 2030 13.17273 2035 12.72326 2040 12.27294 2045 11.83618 2050 11.38874 2055 10.95437 2060 10.56162 2065 10.18567 2070 9.8516 2075 9.5089 2080 9.19301 2085 8.88724 2090 8.61066 2095 8.33701 2100 8.06682