Year Percent 1950 15.16559 1955 14.74334 1960 14.24893 1965 13.76309 1970 13.38261 1975 13.11802 1980 12.81969 1985 11.74764 1990 10.81472 1995 12.67035 2000 14.02712 2005 15.9657 2010 18.91272 2015 23.78928 2020 27.92515 2025 29.09823 2030 29.75263 2035 29.54562 2040 28.17335 2045 27.29553 2050 26.54598 2055 26.07788 2060 26.84832 2065 27.5601 2070 27.43185 2075 26.703 2080 25.52262 2085 24.72653 2090 24.5216 2095 24.6269 2100 24.66926