Year Percent 1950 15.78507 1955 16.51033 1960 17.67105 1965 15.32245 1970 16.29985 1975 14.95082 1980 16.29482 1985 18.91565 1990 23.73226 1995 25.59168 2000 27.50614 2005 28.02864 2010 28.25984 2015 27.16126 2020 24.4095 2025 21.59199 2030 18.90638 2035 19.02862 2040 20.24205 2045 22.21899 2050 24.89561 2055 25.59807 2060 25.55237 2065 25.14801 2070 24.40075 2075 23.5387 2080 23.05437 2085 22.72495 2090 22.25338 2095 21.66135 2100 21.14322