Year Percent 1950 16.74223 1955 17.55724 1960 18.46473 1965 18.79341 1970 18.9485 1975 19.13007 1980 18.75889 1985 18.14401 1990 21.7206 1995 21.34956 2000 21.05422 2005 22.0209 2010 22.99473 2015 25.37245 2020 27.72335 2025 30.25436 2030 32.51025 2035 34.39945 2040 35.58578 2045 36.23809 2050 36.35093 2055 36.65901 2060 36.61811 2065 36.75487 2070 36.81893 2075 36.95048 2080 37.16248 2085 37.46159 2090 37.83294 2095 38.25349 2100 38.71134