Year Percent 1950 27.72802 1955 30.73714 1960 32.37169 1965 31.7063 1970 28.64143 1975 25.27608 1980 24.24948 1985 24.5343 1990 26.19691 1995 28.23896 2000 29.68801 2005 34.05202 2010 38.11115 2015 39.79784 2020 38.09567 2025 33.61121 2030 29.34471 2035 27.60128 2040 27.71458 2045 27.7908 2050 26.43679 2055 23.90397 2060 21.84544 2065 21.01831 2070 21.16927 2075 21.46639 2080 21.27952 2085 20.61089 2090 19.94753 2095 19.69684 2100 19.85653