Year Percent 1950 12.50328 1955 12.41888 1960 13.99246 1965 13.90644 1970 13.72414 1975 13.51041 1980 13.67804 1985 13.5007 1990 13.27621 1995 12.22189 2000 11.10259 2005 10.45867 2010 10.06173 2015 9.72967 2020 9.60523 2025 9.10754 2030 8.57812 2035 8.08952 2040 7.70341 2045 7.41402 2050 7.15309 2055 6.87402 2060 6.59673 2065 6.34091 2070 6.14124 2075 5.98557 2080 5.84773 2085 5.7258 2090 5.60541 2095 5.49875 2100 5.4146