Year Percent 1950 27.2531 1955 27.44923 1960 25.1818 1965 24.77163 1970 24.29313 1975 24.1179 1980 25.04621 1985 23.90349 1990 24.61736 1995 25.39216 2000 27.03251 2005 28.97209 2010 28.77558 2015 28.64797 2020 27.52724 2025 26.33689 2030 25.452 2035 24.99538 2040 24.36142 2045 23.77042 2050 23.55608 2055 23.40802 2060 23.72146 2065 23.93667 2070 23.70623 2075 23.33084 2080 22.9746 2085 22.82695 2090 22.82693 2095 22.87021 2100 22.80992