Year Percent 1950 23.01908 1955 25.9474 1960 24.38359 1965 25.01286 1970 26.39177 1975 24.89442 1980 27.89481 1985 25.98186 1990 24.06858 1995 26.22899 2000 26.06833 2005 28.27135 2010 28.53165 2015 27.84894 2020 27.78459 2025 28.34983 2030 29.95115 2035 29.45265 2040 27.10115 2045 23.88174 2050 21.76787 2055 21.75608 2060 23.01205 2065 24.32104 2070 24.00275 2075 23.17116 2080 22.58961 2085 22.6059 2090 23.07377 2095 23.51301 2100 23.49671