Year Percent 1950 26.76073 1955 27.99393 1960 28.74709 1965 29.21076 1970 29.25893 1975 28.23414 1980 27.66019 1985 27.18732 1990 26.53404 1995 23.16229 2000 24.44975 2005 28.66221 2010 30.57657 2015 30.90132 2020 30.72894 2025 30.87216 2030 31.60067 2035 32.54658 2040 33.06784 2045 32.58081 2050 31.66019 2055 31.13375 2060 30.89261 2065 30.6717 2070 30.25893 2075 29.6196 2080 28.88692 2085 28.21392 2090 27.64377 2095 27.08775 2100 26.47483