Year Percent 1950 12.63183 1955 15.23884 1960 16.26623 1965 17.54051 1970 19.0432 1975 20.02795 1980 19.99648 1985 19.73539 1990 18.97715 1995 16.25394 2000 16.66579 2005 17.15959 2010 17.37771 2015 15.23987 2020 13.62997 2025 12.67582 2030 12.04181 2035 11.44954 2040 10.75189 2045 9.98061 2050 9.20849 2055 8.54162 2060 7.99931 2065 7.5305 2070 7.10646 2075 6.69296 2080 6.30957 2085 5.97591 2090 5.70368 2095 5.49756 2100 5.32772