Year Percent 1950 4.54468 1955 4.51547 1960 4.50549 1965 4.62865 1970 4.91858 1975 5.34417 1980 5.56608 1985 5.84525 1990 7.06862 1995 7.6185 2000 8.33603 2005 9.44901 2010 11.05162 2015 12.75865 2020 15.15904 2025 17.98021 2030 20.55463 2035 22.59352 2040 24.96229 2045 27.68734 2050 30.45587 2055 32.92929 2060 34.95518 2065 36.27525 2070 37.47821 2075 38.3977 2080 39.06267 2085 39.46269 2090 39.70289 2095 39.8725 2100 40.02736