Year Percent 1950 28.7144 1955 28.75653 1960 27.15031 1965 26.2615 1970 25.52296 1975 25.41008 1980 25.97371 1985 26.15727 1990 26.28175 1995 25.95584 2000 25.92541 2005 26.24715 2010 26.72467 2015 27.35637 2020 27.97988 2025 28.77473 2030 29.58667 2035 30.24355 2040 30.82003 2045 31.21429 2050 31.48218 2055 31.61811 2060 31.56824 2065 31.36138 2070 31.01946 2075 30.59737 2080 30.13209 2085 29.62722 2090 29.09495 2095 28.53925 2100 27.97543