Year Percent 1950 6.35455 1955 6.23542 1960 6.12199 1965 5.85657 1970 5.85507 1975 5.73519 1980 5.6783 1985 5.55918 1990 6.19645 1995 6.62919 2000 7.15154 2005 7.76431 2010 8.3611 2015 9.4362 2020 10.49273 2025 11.58233 2030 12.6837 2035 13.7617 2040 14.86219 2045 16.3735 2050 18.11565 2055 19.7258 2060 21.19294 2065 22.56647 2070 24.00501 2075 25.61947 2080 27.11517 2085 28.4332 2090 29.57823 2095 30.59479 2100 31.52565