Year Percent 1950 27.10552 1955 26.88534 1960 26.58475 1965 26.32119 1970 26.28088 1975 26.3079 1980 25.8395 1985 28.70743 1990 28.7596 1995 28.01289 2000 31.31337 2005 33.29637 2010 35.76066 2015 37.48804 2020 35.137 2025 31.93285 2030 29.55185 2035 28.12004 2040 28.63821 2045 29.13527 2050 28.48371 2055 27.15542 2060 25.4289 2065 24.255 2070 23.83834 2075 23.77868 2080 23.62982 2085 23.14327 2090 22.42277 2095 21.77799 2100 21.43224