Year Percent 1950 8.76148 1955 9.04306 1960 9.66757 1965 10.82027 1970 13.7173 1975 14.63123 1980 14.59185 1985 14.75709 1990 19.24958 1995 20.78305 2000 21.98842 2005 22.4866 2010 23.95123 2015 25.71652 2020 27.81153 2025 30.12686 2030 33.18562 2035 36.15185 2040 39.03045 2045 41.08826 2050 41.60417 2055 41.6483 2060 41.66289 2065 41.63792 2070 42.0778 2075 41.9839 2080 41.52072 2085 40.99524 2090 40.68346 2095 40.58659 2100 40.67534