Year Percent 1950 23.11245 1955 21.68189 1960 19.53771 1965 18.69164 1970 19.00028 1975 21.15731 1980 23.54921 1985 23.87366 1990 23.01628 1995 22.84682 2000 24.11174 2005 26.93815 2010 28.94366 2015 29.72862 2020 28.33245 2025 26.68406 2030 26.78201 2035 27.84693 2040 28.09845 2045 26.96886 2050 25.24237 2055 23.68666 2060 23.70859 2065 25.01988 2070 25.77213 2075 25.30149 2080 24.48786 2085 23.7509 2090 23.61953 2095 24.06979 2100 24.51152