Year Percent 1950 30.11921 1955 29.5231 1960 27.7742 1965 25.75042 1970 25.81368 1975 25.60713 1980 26.4261 1985 27.45732 1990 27.5746 1995 27.92195 2000 29.11556 2005 31.08328 2010 33.05203 2015 32.47773 2020 30.72154 2025 29.16372 2030 28.02426 2035 29.38481 2040 30.40555 2045 30.54534 2050 30.22443 2055 28.91388 2060 28.46079 2065 28.44264 2070 28.39697 2075 27.94885 2080 27.14838 2085 26.37607 2090 25.7598 2095 25.26767 2100 24.7899