Year Percent 1950 5.09332 1955 5.08648 1960 4.97015 1965 4.78478 1970 4.55905 1975 4.36456 1980 4.37619 1985 4.18206 1990 4.56344 1995 4.60123 2000 4.58492 2005 4.54551 2010 4.2525 2015 4.2392 2020 4.26108 2025 4.37566 2030 4.63671 2035 5.27372 2040 6.45682 2045 8.05082 2050 9.6704 2055 11.2093 2060 12.61486 2065 14.05525 2070 15.84804 2075 17.98318 2080 19.86407 2085 21.51163 2090 23.04241 2095 24.55178 2100 26.02141