Year Percent 1950 27.17885 1955 27.23801 1960 26.7726 1965 26.2495 1970 26.05793 1975 26.43835 1980 26.61731 1985 26.99307 1990 28.02989 1995 28.935 2000 29.20752 2005 29.07856 2010 29.45533 2015 30.89204 2020 32.27232 2025 32.45974 2030 31.75708 2035 29.94376 2040 28.16794 2045 27.32164 2050 26.52208 2055 25.50339 2060 24.1342 2065 22.81498 2070 21.79602 2075 21.10884 2080 20.65383 2085 20.27991 2090 19.90886 2095 19.56377 2100 19.30891