Year Percent 1950 18.78691 1955 18.32639 1960 18.76506 1965 19.24258 1970 17.31672 1975 15.21525 1980 14.77787 1985 14.19118 1990 13.7344 1995 12.44646 2000 11.32149 2005 10.55354 2010 9.91973 2015 9.29553 2020 8.63887 2025 8.01337 2030 7.47139 2035 6.99411 2040 6.58779 2045 6.24134 2050 5.9276 2055 5.66275 2060 5.43653 2065 5.25141 2070 5.0975 2075 4.9679 2080 4.85931 2085 4.77092 2090 4.6945 2095 4.63658 2100 4.59261