Year Percent 1950 5.5832 1955 5.16119 1960 4.89538 1965 4.72122 1970 4.59324 1975 6.20079 1980 5.07266 1985 4.77189 1990 4.98853 1995 5.327 2000 4.78677 2005 4.92523 2010 5.54999 2015 7.00997 2020 7.90102 2025 8.42677 2030 8.03432 2035 7.11377 2040 7.10729 2045 8.97477 2050 11.71177 2055 14.59455 2060 17.20249 2065 18.95626 2070 19.76082 2075 20.20229 2080 21.0224 2085 22.27286 2090 23.75877 2095 25.0053 2100 25.78806