Year Percent 1950 11.39524 1955 14.02015 1960 15.92633 1965 15.60405 1970 14.97509 1975 13.42513 1980 12.03299 1985 11.16619 1990 10.21307 1995 10.43541 2000 10.31411 2005 9.66932 2010 9.1869 2015 8.23768 2020 7.74444 2025 7.46069 2030 7.25069 2035 6.94588 2040 6.56708 2045 6.18932 2050 5.87859 2055 5.67141 2060 5.53288 2065 5.39181 2070 5.21357 2075 5.02247 2080 4.855 2085 4.74398 2090 4.67936 2095 4.62779 2100 4.57597