Year Percent 1950 30.22738 1955 29.01092 1960 28.00133 1965 27.1119 1970 26.51403 1975 26.01329 1980 25.38369 1985 24.97608 1990 25.34328 1995 26.05156 2000 26.89891 2005 27.67747 2010 27.994 2015 28.28954 2020 28.63021 2025 29.19639 2030 30.06284 2035 30.8019 2040 31.28386 2045 31.51948 2050 31.57627 2055 31.62214 2060 31.66072 2065 31.60465 2070 31.39631 2075 31.08647 2080 30.70696 2085 30.3263 2090 29.96074 2095 29.56998 2100 29.15418