Year Percent 1950 14.07458 1955 15.5545 1960 17.20963 1965 18.91393 1970 20.32304 1975 21.35479 1980 19.98622 1985 20.23721 1990 24.76399 1995 24.64651 2000 26.61306 2005 27.69538 2010 28.57715 2015 29.73496 2020 31.3666 2025 34.02925 2030 36.5006 2035 37.21123 2040 37.57294 2045 38.32466 2050 39.24455 2055 39.46473 2060 39.32544 2065 38.98149 2070 38.71585 2075 38.72088 2080 38.90641 2085 39.18116 2090 39.44907 2095 39.6902 2100 39.9432