Year Percent 1950 27.59295 1955 26.65864 1960 25.4219 1965 25.14486 1970 24.35319 1975 24.99487 1980 25.70922 1985 23.38855 1990 25.52066 1995 23.65781 2000 24.05821 2005 22.36619 2010 22.34839 2015 22.5303 2020 22.88357 2025 24.26102 2030 25.86908 2035 27.36814 2040 28.27095 2045 28.88478 2050 29.48982 2055 30.10586 2060 30.69144 2065 31.17265 2070 31.52676 2075 31.72767 2080 31.78824 2085 31.71075 2090 31.49582 2095 31.19111 2100 30.78585