Year Percent 1950 29.04966 1955 29.88006 1960 28.98491 1965 25.14874 1970 22.08118 1975 22.14957 1980 24.57279 1985 27.90462 1990 30.90307 1995 31.51642 2000 31.51815 2005 31.00716 2010 31.23055 2015 31.86278 2020 31.32321 2025 30.0242 2030 28.87251 2035 28.35438 2040 28.23917 2045 27.88647 2050 27.10623 2055 25.63004 2060 24.43795 2065 23.63474 2070 23.13834 2075 22.74823 2080 22.30027 2085 21.7719 2090 21.26293 2095 20.8857 2100 20.66032