Year Percent 1950 29.09273 1955 27.71208 1960 26.17142 1965 25.73572 1970 26.10191 1975 28.53568 1980 29.97925 1985 32.17891 1990 31.62866 1995 31.24375 2000 28.84852 2005 27.48693 2010 26.89477 2015 26.61729 2020 27.24656 2025 27.0253 2030 26.53493 2035 25.38414 2040 24.83614 2045 24.81223 2050 24.37803 2055 23.99365 2060 23.55687 2065 23.11875 2070 22.7345 2075 22.45045 2080 22.2196 2085 21.99789 2090 21.77467 2095 21.54581 2100 21.33045