Year Percent 1950 29.66697 1955 27.05754 1960 25.89717 1965 25.30472 1970 23.82925 1975 25.01914 1980 24.92053 1985 24.73624 1990 25.88564 1995 27.21541 2000 29.3939 2005 30.50011 2010 30.08606 2015 29.98341 2020 29.84911 2025 29.74124 2030 29.85775 2035 30.22331 2040 30.40455 2045 30.5755 2050 30.53335 2055 30.3053 2060 30.14497 2065 30.02111 2070 29.86333 2075 29.63106 2080 29.31494 2085 28.97242 2090 28.61335 2095 28.24921 2100 27.87012