Year Percent 1950 13.37027 1955 12.80225 1960 13.04992 1965 12.86317 1970 12.70396 1975 12.64041 1980 11.9449 1985 11.59994 1990 12.7958 1995 12.85972 2000 13.13094 2005 13.63785 2010 15.10512 2015 17.57272 2020 19.22487 2025 21.33282 2030 23.19014 2035 25.65382 2040 27.77903 2045 29.13324 2050 29.26364 2055 28.854 2060 28.74848 2065 29.31568 2070 30.50478 2075 31.68955 2080 32.52795 2085 33.04386 2090 33.45964 2095 33.97036 2100 34.59793