Year Percent 1950 14.66928 1955 14.23643 1960 13.75442 1965 11.57907 1970 13.23947 1975 14.21421 1980 14.10679 1985 16.25983 1990 20.46791 1995 21.49044 2000 22.05226 2005 21.52247 2010 23.45032 2015 30.10511 2020 31.81389 2025 31.15623 2030 31.1838 2035 30.53988 2040 31.9131 2045 33.96738 2050 35.01412 2055 35.15936 2060 33.47055 2065 31.54344 2070 29.65556 2075 28.31001 2080 28.03043 2085 27.95423 2090 27.75221 2095 27.46081 2100 27.14477