Year Percent 1950 30.1539 1955 28.58821 1960 24.52064 1965 22.82495 1970 20.8139 1975 20.22158 1980 25.63164 1985 28.28567 1990 30.38416 1995 31.50851 2000 30.83857 2005 29.74308 2010 30.2865 2015 31.61221 2020 32.57635 2025 31.70232 2030 29.44738 2035 26.85602 2040 25.40409 2045 24.92048 2050 24.51489 2055 24.1002 2060 22.31969 2065 20.82764 2070 19.89116 2075 19.48564 2080 19.34142 2085 19.06724 2090 18.53756 2095 17.87889 2100 17.37464