Year Percent 1950 12.98077 1955 13.70162 1960 14.31638 1965 15.9114 1970 17.77362 1975 16.42722 1980 15.01267 1985 14.10559 1990 12.37906 1995 11.89372 2000 11.02906 2005 9.55691 2010 7.58952 2015 6.17135 2020 5.87794 2025 5.61629 2030 5.29702 2035 4.97697 2040 4.63576 2045 4.32977 2050 4.1612 2055 4.11096 2060 4.10233 2065 4.07713 2070 4.0284 2075 3.99015 2080 3.99404 2085 4.05316 2090 4.13372 2095 4.2094 2100 4.24733