Year Percent 1950 20.09445 1955 21.27869 1960 21.61755 1965 22.13409 1970 23.50779 1975 24.01389 1980 25.10729 1985 24.82496 1990 24.26935 1995 23.92212 2000 24.80914 2005 26.3628 2010 27.60543 2015 29.44598 2020 30.46547 2025 30.76887 2030 28.97454 2035 26.81983 2040 24.65519 2045 23.20051 2050 23.63799 2055 23.92013 2060 23.62245 2065 22.96335 2070 21.7869 2075 21.34355 2080 21.59147 2085 22.11756 2090 22.39326 2095 22.27138 2100 21.85739