Year Percent 1950 27.20005 1955 26.64511 1960 28.12266 1965 25.70841 1970 26.65676 1975 27.76587 1980 29.30041 1985 30.97715 1990 30.27021 1995 29.43824 2000 28.07558 2005 26.85465 2010 25.62807 2015 24.21913 2020 23.85178 2025 23.56959 2030 23.54185 2035 23.59982 2040 23.40888 2045 23.06007 2050 22.72545 2055 22.62054 2060 22.66299 2065 22.69014 2070 22.5876 2075 22.33939 2080 22.04583 2085 21.82125 2090 21.68215 2095 21.58201 2100 21.45966