Year Percent 1950 22.99907 1955 23.58647 1960 21.05979 1965 21.71283 1970 21.92732 1975 21.54511 1980 22.29811 1985 21.22397 1990 21.57056 1995 23.56841 2000 25.99852 2005 27.50024 2010 27.77801 2015 27.40538 2020 27.98756 2025 28.76189 2030 29.83113 2035 29.49894 2040 27.11437 2045 24.5797 2050 22.81179 2055 21.95917 2060 22.45406 2065 23.29744 2070 23.36837 2075 22.96322 2080 22.44914 2085 22.17024 2090 22.28232 2095 22.62086 2100 22.80264