Year Percent 1950 8.78514 1955 9.19248 1960 9.60767 1965 10.42552 1970 11.14995 1975 11.49023 1980 11.66951 1985 12.73833 1990 16.36214 1995 18.15976 2000 18.888 2005 19.08047 2010 19.90551 2015 21.98879 2020 24.5219 2025 27.73532 2030 31.19213 2035 35 2040 38.32899 2045 39.61505 2050 39.48839 2055 38.83225 2060 37.8919 2065 37.49171 2070 37.74696 2075 37.68139 2080 37.62553 2085 37.55937 2090 37.53463 2095 37.62121 2100 37.84726