Year Percent 1950 6.9521 1955 6.53084 1960 5.81624 1965 5.18164 1970 4.63833 1975 4.22985 1980 4.04115 1985 4.1197 1990 4.54727 1995 4.5891 2000 4.46307 2005 4.82952 2010 4.91029 2015 5.84686 2020 6.81674 2025 7.51068 2030 8.47777 2035 9.5617 2040 11.10359 2045 12.94825 2050 14.63052 2055 16.15879 2060 18.4116 2065 20.95713 2070 23.50755 2075 25.73913 2080 27.39279 2085 28.82103 2090 30.10989 2095 31.32967 2100 32.47123