Year Percent 1950 26.59357 1955 25.95004 1960 25.64238 1965 25.68208 1970 25.55756 1975 26.83823 1980 28.23456 1985 29.51894 1990 30.93963 1995 31.49075 2000 31.58743 2005 31.53821 2010 31.66005 2015 31.53873 2020 31.22949 2025 30.50969 2030 29.6859 2035 28.92163 2040 28.18983 2045 27.58478 2050 26.82846 2055 25.99438 2060 25.16958 2065 24.40684 2070 23.70891 2075 23.06537 2080 22.47584 2085 21.94891 2090 21.48621 2095 21.09299 2100 20.75611