Year Percent 1950 21.84181 1955 23.74488 1960 21.68792 1965 22.11766 1970 24.07227 1975 23.58826 1980 27.21122 1985 25.90438 1990 24.28773 1995 26.26858 2000 26.14366 2005 28.35588 2010 28.35529 2015 27.89631 2020 28.03758 2025 29.03235 2030 31.02937 2035 30.73511 2040 28.45097 2045 25.11003 2050 22.99112 2055 23.05252 2060 24.3863 2065 25.69399 2070 25.26794 2075 24.28653 2080 23.58456 2085 23.52664 2090 23.96255 2095 24.39199 2100 24.3584