Year Percent 1950 19.35481 1955 18.48633 1960 18.39742 1965 17.32653 1970 16.13183 1975 15.74647 1980 15.8128 1985 15.95184 1990 16.77022 1995 19.45781 2000 21.78151 2005 25.40805 2010 29.34122 2015 30.80249 2020 30.94397 2025 30.32002 2030 30.31694 2035 28.93895 2040 27.83862 2045 26.29021 2050 23.22871 2055 22.64909 2060 23.36084 2065 23.81677 2070 23.65567 2075 22.95073 2080 22.48868 2085 22.53594 2090 22.80996 2095 22.97564 2100 22.88633