Year Percent 1950 27.64437 1955 27.94155 1960 27.91062 1965 27.71476 1970 27.73012 1975 26.98615 1980 26.87413 1985 27.29901 1990 27.89614 1995 28.70669 2000 29.28899 2005 29.53692 2010 29.71335 2015 30.28664 2020 30.7493 2025 30.96496 2030 31.36068 2035 31.86008 2040 32.00626 2045 31.94658 2050 31.52631 2055 30.92567 2060 30.56442 2065 30.4173 2070 30.29862 2075 30.05776 2080 29.69904 2085 29.27817 2090 28.8761 2095 28.52271 2100 28.16904