Year Percent 1950 14.4736 1955 15.06301 1960 15.44729 1965 15.77521 1970 16.00483 1975 15.95527 1980 15.91273 1985 16.00352 1990 16.89828 1995 18.22336 2000 21.4484 2005 22.951 2010 23.59741 2015 24.60573 2020 25.55395 2025 25.53374 2030 24.6621 2035 23.94551 2040 22.94574 2045 23.1337 2050 24.45216 2055 25.26281 2060 25.56121 2065 24.93534 2070 23.81044 2075 23.24795 2080 23.13567 2085 23.24047 2090 23.17437 2095 22.72796 2100 22.10155