Year Percent 1950 4.13975 1955 4.15949 1960 4.06314 1965 3.91001 1970 3.83355 1975 4.06241 1980 4.90339 1985 4.75875 1990 4.41331 1995 3.59787 2000 3.66895 2005 3.69269 2010 3.93667 2015 5.01328 2020 6.59611 2025 8.11899 2030 9.59633 2035 11.19202 2040 13.08758 2045 15.06775 2050 16.86064 2055 18.3144 2060 19.41445 2065 20.41797 2070 21.42995 2075 22.8111 2080 24.16099 2085 25.48533 2090 26.71303 2095 27.8111 2100 28.80467