Year Percent 1950 27.96977 1955 29.12839 1960 29.66302 1965 29.65541 1970 29.83301 1975 28.25582 1980 27.21494 1985 26.5111 1990 26.52968 1995 27.55634 2000 29.2249 2005 31.93917 2010 34.94625 2015 36.91536 2020 37.12298 2025 35.83217 2030 33.45212 2035 31.21433 2040 29.67519 2045 28.47392 2050 27.01772 2055 25.62821 2060 24.16968 2065 23.00458 2070 22.25275 2075 21.82838 2080 21.54983 2085 21.28423 2090 21.00958 2095 20.7868 2100 20.67413