Year Percent 1950 14.27518 1955 13.88753 1960 13.57272 1965 13.27519 1970 13.04312 1975 12.97951 1980 13.6775 1985 13.1556 1990 12.83513 1995 13.73324 2000 14.93141 2005 17.01706 2010 18.53792 2015 18.83736 2020 17.57206 2025 21.47581 2030 22.53224 2035 24.61521 2040 27.02854 2045 24.67398 2050 25.00718 2055 24.86522 2060 25.23143 2065 25.73507 2070 25.64287 2075 25.22524 2080 24.85959 2085 24.75087 2090 24.6664 2095 24.42565 2100 24.0197