Year Percent 1950 31.01383 1955 29.7216 1960 28.12307 1965 25.878 1970 24.24575 1975 24.38712 1980 25.14937 1985 26.24995 1990 27.29797 1995 27.58398 2000 27.92267 2005 28.1319 2010 28.40904 2015 29.0258 2020 29.87154 2025 30.56758 2030 31.01653 2035 31.10735 2040 31.06976 2045 31.14027 2050 31.21799 2055 31.21775 2060 31.00581 2065 30.66604 2070 30.30387 2075 29.97692 2080 29.63873 2085 29.25536 2090 28.8193 2095 28.32896 2100 27.82622