Year Percent 1950 5.13514 1955 4.62138 1960 4.26276 1965 4.10082 1970 4.06721 1975 4.11644 1980 4.19549 1985 4.2853 1990 4.59367 1995 4.76923 2000 4.94801 2005 5.13942 2010 5.25371 2015 5.14002 2020 5.19327 2025 5.37549 2030 5.66577 2035 6.00689 2040 6.40877 2045 6.87112 2050 7.55257 2055 8.40028 2060 9.36938 2065 10.34697 2070 11.37935 2075 12.44917 2080 13.59121 2085 14.78613 2090 15.98301 2095 17.16612 2100 18.34642