Year Percent 1950 27.80078 1955 27.10271 1960 26.9969 1965 25.47119 1970 24.80459 1975 26.56741 1980 27.15652 1985 28.73649 1990 29.63327 1995 32.35524 2000 33.4232 2005 31.22012 2010 32.32576 2015 34.16647 2020 35.01912 2025 33.31973 2030 29.01527 2035 24.99696 2040 22.36369 2045 21.69867 2050 22.53291 2055 22.59549 2060 21.99516 2065 20.56908 2070 19.32832 2075 19.01253 2080 19.52488 2085 20.18036 2090 20.37591 2095 20.01146 2100 19.4466