Year Percent 1950 26.75969 1955 29.15903 1960 32.50817 1965 33.99072 1970 33.06993 1975 32.22659 1980 31.35284 1985 31.22695 1990 31.41356 1995 30.48666 2000 30.0777 2005 30.58715 2010 31.49445 2015 29.95272 2020 27.20882 2025 24.63747 2030 23.09147 2035 22.87375 2040 24.69535 2045 25.41348 2050 24.27544 2055 23.05581 2060 22.42616 2065 22.52435 2070 23.18325 2075 23.79604 2080 23.73858 2085 23.06809 2090 22.37021 2095 22.08619 2100 22.25499