Year Percent 1950 19.48221 1955 19.7276 1960 18.48681 1965 18.68909 1970 19.76076 1975 22.04971 1980 22.6557 1985 20.79843 1990 23.80839 1995 26.02625 2000 27.88613 2005 29.33339 2010 27.45734 2015 26.40034 2020 26.1516 2025 26.75819 2030 28.4762 2035 29.33647 2040 28.51871 2045 26.46331 2050 24.33398 2055 22.76316 2060 22.27703 2065 22.89079 2070 23.29421 2075 23.17159 2080 22.75775 2085 22.25875 2090 22.02026 2095 22.14857 2100 22.41129