Year Percent 1950 5.88276 1955 5.41297 1960 5.0612 1965 4.76651 1970 4.58916 1975 4.46592 1980 4.18909 1985 3.89485 1990 3.87521 1995 4.58302 2000 4.32418 2005 4.23579 2010 4.38196 2015 4.50643 2020 4.69412 2025 4.94679 2030 5.21914 2035 5.65061 2040 6.6615 2045 8.06668 2050 9.84999 2055 11.83761 2060 13.4348 2065 14.93089 2070 16.56806 2075 18.43103 2080 20.30704 2085 22.09343 2090 23.76092 2095 25.32411 2100 26.77436