Year Percent 1950 20.41755 1955 19.83031 1960 19.14306 1965 18.95509 1970 19.26624 1975 19.03981 1980 18.62218 1985 18.64863 1990 19.51538 1995 21.2039 2000 23.79943 2005 25.89175 2010 25.9776 2015 25.73411 2020 24.93837 2025 24.43738 2030 24.35164 2035 24.98169 2040 24.78143 2045 24.2807 2050 24.2608 2055 23.74327 2060 23.79658 2065 23.84865 2070 23.42352 2075 22.94491 2080 22.61629 2085 22.37809 2090 22.24496 2095 22.13694 2100 21.97139