Year Percent 1950 5.13755 1955 5.06222 1960 5.4747 1965 5.41946 1970 5.41604 1975 5.18355 1980 4.90561 1985 4.63203 1990 5.20306 1995 5.62798 2000 6.3979 2005 7.0394 2010 7.80541 2015 8.93955 2020 10.08405 2025 11.55825 2030 13.26854 2035 15.23606 2040 17.71468 2045 20.50801 2050 23.01939 2055 24.82471 2060 25.43584 2065 25.6572 2070 27.03089 2075 29.40099 2080 31.20482 2085 32.43638 2090 33.22566 2095 33.84676 2100 34.52728