Year Percent 1950 13.40549 1955 12.41151 1960 13.57908 1965 13.89701 1970 14.24744 1975 13.9566 1980 13.34796 1985 13.955 1990 15.33043 1995 14.65554 2000 13.7702 2005 13.09659 2010 12.2277 2015 11.64244 2020 10.91027 2025 10.34042 2030 9.73556 2035 9.16741 2040 8.66532 2045 8.21779 2050 7.83976 2055 7.47895 2060 7.17709 2065 6.90858 2070 6.69822 2075 6.52831 2080 6.38203 2085 6.24664 2090 6.12974 2095 6.03154 2100 5.94671