Year Percent 1950 5.58513 1955 5.14261 1960 4.82574 1965 4.71932 1970 4.84147 1975 4.95822 1980 4.96185 1985 4.81233 1990 4.93593 1995 4.81012 2000 4.7277 2005 4.62259 2010 4.49795 2015 4.71467 2020 5.12212 2025 5.58755 2030 6.06795 2035 6.58685 2040 7.23187 2045 8.10815 2050 9.07102 2055 9.95762 2060 10.79871 2065 11.6779 2070 12.68339 2075 13.82248 2080 14.92936 2085 15.98121 2090 16.98886 2095 17.99337 2100 19.02359