Year Percent 1950 41.87543 1955 37.81623 1960 32.76848 1965 28.25114 1970 26.33515 1975 27.33876 1980 34.5883 1985 38.26814 1990 38.25453 1995 36.21475 2000 32.18985 2005 28.90624 2010 27.70185 2015 27.11934 2020 25.55009 2025 22.57013 2030 21.06614 2035 19.9989 2040 20.76594 2045 23.01664 2050 24.3961 2055 24.70761 2060 23.67428 2065 22.40333 2070 21.59885 2075 21.827 2080 22.56954 2085 23.04838 2090 22.84494 2095 22.11121 2100 21.30098