Year Percent 1950 27.52962 1955 26.56094 1960 26.07931 1965 24.98932 1970 23.98791 1975 24.52653 1980 25.59748 1985 27.39267 1990 29.15815 1995 30.64687 2000 32.99829 2005 35.54648 2010 36.34235 2015 35.17692 2020 32.05362 2025 28.3925 2030 26.96646 2035 27.78093 2040 29.15443 2045 29.94832 2050 28.63312 2055 26.03639 2060 24.38834 2065 23.84673 2070 24.05733 2075 24.27277 2080 23.9666 2085 23.14964 2090 22.20666 2095 21.60241 2100 21.46862