Year Percent 1950 31.52226 1955 28.46191 1960 25.47651 1965 24.28384 1970 25.77474 1975 27.74918 1980 30.02644 1985 31.2795 1990 31.43109 1995 31.03254 2000 29.47832 2005 27.75234 2010 27.00023 2015 27.43248 2020 27.36936 2025 26.7875 2030 26.18788 2035 25.31983 2040 24.81226 2045 24.70578 2050 24.50525 2055 24.44493 2060 24.16005 2065 23.77818 2070 23.4183 2075 23.14659 2080 22.95117 2085 22.77376 2090 22.55633 2095 22.28718 2100 22.00992