Year Percent 1950 5.32447 1955 5.17701 1960 4.93271 1965 4.77515 1970 4.67974 1975 4.56974 1980 4.49503 1985 4.45826 1990 4.85829 1995 5.00179 2000 5.06839 2005 5.16685 2010 5.39875 2015 5.69134 2020 6.03541 2025 6.41951 2030 6.87359 2035 7.341 2040 7.88759 2045 8.48251 2050 9.07203 2055 9.92726 2060 11.00177 2065 12.17903 2070 13.34773 2075 14.44981 2080 15.5209 2085 16.60891 2090 17.74865 2095 18.9267 2100 20.09629