Year Percent 1950 13.41826 1955 14.65321 1960 15.52093 1965 15.37726 1970 15.45819 1975 15.06845 1980 12.92889 1985 12.6566 1990 12.34347 1995 11.48127 2000 10.67781 2005 9.51909 2010 8.90059 2015 8.09744 2020 7.40088 2025 6.86488 2030 6.3693 2035 5.98319 2040 5.6736 2045 5.42837 2050 5.23952 2055 5.08006 2060 4.9532 2065 4.85107 2070 4.77727 2075 4.72716 2080 4.7002 2085 4.67909 2090 4.67045 2095 4.66433 2100 4.66337