Year Percent 1950 21.74395 1955 22.43359 1960 21.88334 1965 21.81714 1970 22.10556 1975 22.00671 1980 22.95211 1985 23.62003 1990 26.56361 1995 28.65083 2000 30.07978 2005 30.72052 2010 28.48446 2015 26.33929 2020 25.27087 2025 24.6301 2030 24.45052 2035 25.30464 2040 25.12983 2045 24.57488 2050 24.43522 2055 23.96102 2060 24.09663 2065 24.31825 2070 24.14475 2075 23.93588 2080 23.64575 2085 23.41058 2090 23.2893 2095 23.22669 2100 23.12416