Year Percent 1950 15.51471 1955 12.09584 1960 12.29206 1965 14.70183 1970 15.61902 1975 15.66607 1980 15.2552 1985 14.62975 1990 16.44696 1995 16.35147 2000 13.7944 2005 10.4328 2010 8.55264 2015 8.63702 2020 9.26715 2025 8.58088 2030 7.26999 2035 6.02962 2040 5.39806 2045 5.38076 2050 5.53188 2055 5.43765 2060 5.05665 2065 4.64816 2070 4.43843 2075 4.48265 2080 4.62879 2085 4.70226 2090 4.62539 2095 4.4756 2100 4.37803