Year Percent 1950 17.1678 1955 16.32871 1960 15.14322 1965 15.15191 1970 16.48829 1975 18.27277 1980 20.877 1985 21.51312 1990 21.62855 1995 23.13761 2000 25.08377 2005 26.71304 2010 27.31925 2015 26.48501 2020 26.12771 2025 26.27776 2030 26.80606 2035 27.09846 2040 26.95896 2045 26.11948 2050 25.90887 2055 25.33547 2060 24.73629 2065 24.27691 2070 23.59214 2075 23.13325 2080 22.90969 2085 22.8053 2090 22.71033 2095 22.59157 2100 22.41895