Year Percent 1950 15.51304 1955 15.50987 1960 15.3065 1965 15.17183 1970 15.17236 1975 15.56755 1980 15.30373 1985 14.29527 1990 14.46206 1995 14.86748 2000 15.90809 2005 17.04213 2010 17.49171 2015 18.01652 2020 19.26302 2025 20.90768 2030 22.58234 2035 23.02943 2040 22.36909 2045 21.74487 2050 21.41004 2055 23.04606 2060 24.50358 2065 25.23808 2070 25.51078 2075 24.90954 2080 24.95612 2085 25.34669 2090 25.69692 2095 25.68344 2100 25.34611