Year Percent 1950 9.02521 1955 8.97447 1960 10.01594 1965 11.48524 1970 12.67183 1975 13.38057 1980 11.8429 1985 12.54044 1990 14.63885 1995 15.01324 2000 15.25604 2005 16.11259 2010 17.82092 2015 20.69429 2020 23.286 2025 25.34388 2030 26.78061 2035 28.94423 2040 31.84915 2045 34.27264 2050 36.20396 2055 37.35477 2060 37.16303 2065 36.46677 2070 36.21122 2075 36.13403 2080 36.21414 2085 36.37347 2090 36.44484 2095 36.41041 2100 36.47004