Year Percent 1950 13.68843 1955 15.5756 1960 16.55054 1965 17.53795 1970 18.25289 1975 18.64965 1980 19.10618 1985 19.29057 1990 19.20261 1995 18.77494 2000 18.2971 2005 17.65535 2010 17.31781 2015 16.75273 2020 15.99299 2025 15.31169 2030 14.65525 2035 14.01176 2040 13.39407 2045 12.77959 2050 12.18937 2055 11.65838 2060 11.15861 2065 10.71072 2070 10.26313 2075 9.85256 2080 9.46204 2085 9.10844 2090 8.76387 2095 8.43016 2100 8.12534