Year Percent 1950 20.30286 1955 21.28644 1960 21.10789 1965 20.06053 1970 21.66662 1975 22.8811 1980 25.2853 1985 25.15689 1990 24.47033 1995 25.58901 2000 26.06125 2005 27.49394 2010 27.54112 2015 28.0847 2020 28.13557 2025 28.56963 2030 30.16745 2035 29.17173 2040 26.69705 2045 24.44518 2050 22.96899 2055 22.98602 2060 24.63676 2065 25.44157 2070 24.40169 2075 23.62675 2080 23.057 2085 23.04715 2090 23.5286 2095 23.94486 2100 23.84042