Year Percent 1950 26.44426 1955 26.30257 1960 25.34988 1965 23.68115 1970 23.17152 1975 23.49739 1980 24.31971 1985 25.48895 1990 26.37629 1995 27.77387 2000 28.70692 2005 29.93513 2010 30.95567 2015 31.16901 2020 31.37596 2025 31.45788 2030 31.7015 2035 31.90032 2040 31.65556 2045 31.19623 2050 30.60019 2055 30.22168 2060 29.81431 2065 29.32407 2070 28.75411 2075 28.14729 2080 27.55037 2085 26.97704 2090 26.39833 2095 25.79326 2100 25.17449