Year Percent 1950 32.89269 1955 27.9775 1960 26.7057 1965 24.21013 1970 26.19393 1975 28.32676 1980 29.17571 1985 30.21647 1990 29.76042 1995 29.16418 2000 29.36811 2005 29.84281 2010 29.52189 2015 28.24491 2020 27.44572 2025 27.15048 2030 27.47197 2035 28.35696 2040 28.47812 2045 28.17332 2050 27.49679 2055 26.55835 2060 26.14728 2065 26.04281 2070 25.9351 2075 25.60241 2080 25.01046 2085 24.30001 2090 23.67518 2095 23.21564 2100 22.89425