Year Percent 1950 13.46619 1955 13.79371 1960 14.66076 1965 13.38761 1970 14.23348 1975 14.69261 1980 15.14368 1985 15.40515 1990 14.83821 1995 13.58772 2000 13.50242 2005 9.6205 2010 8.09698 2015 8.72933 2020 8.33774 2025 6.91565 2030 6.14389 2035 5.95871 2040 5.94042 2045 5.82204 2050 5.56615 2055 5.3213 2060 5.20352 2065 5.18158 2070 5.20036 2075 5.19344 2080 5.16193 2085 5.10653 2090 5.0756 2095 5.06529 2100 5.06699