Year Percent 1950 5.06031 1955 4.80607 1960 4.99333 1965 5.38934 1970 5.70411 1975 5.92638 1980 5.94239 1985 5.73703 1990 6.07868 1995 6.1122 2000 6.26164 2005 6.421 2010 6.49821 2015 7.05123 2020 7.66158 2025 8.46211 2030 9.27574 2035 10.03093 2040 11.2786 2045 13.26607 2050 15.22108 2055 17.00918 2060 18.67015 2065 20.11248 2070 21.49768 2075 22.73103 2080 23.93497 2085 25.06113 2090 26.09289 2095 27.03359 2100 27.88954