Year Percent 1950 13.11323 1955 12.89389 1960 14.54672 1965 14.39606 1970 14.60265 1975 14.42416 1980 13.57347 1985 14.65065 1990 15.43162 1995 16.71225 2000 16.50734 2005 14.73572 2010 13.95722 2015 14.82193 2020 14.98706 2025 14.74674 2030 13.99851 2035 13.17909 2040 12.72058 2045 12.49912 2050 12.1965 2055 11.69831 2060 11.11349 2065 10.5838 2070 10.19223 2075 9.88448 2080 9.54675 2085 9.15518 2090 8.7229 2095 8.35971 2100 8.03872