Year Percent 1950 12.09291 1955 13.9195 1960 15.55631 1965 16.36563 1970 16.80273 1975 16.92109 1980 13.41678 1985 10.68915 1990 11.48619 1995 11.54118 2000 10.87555 2005 10.42798 2010 9.55478 2015 8.93317 2020 8.63035 2025 8.18084 2030 7.7535 2035 7.35265 2040 6.98121 2045 6.66163 2050 6.41102 2055 6.19826 2060 6.01361 2065 5.83435 2070 5.67173 2075 5.53351 2080 5.41449 2085 5.32812 2090 5.25077 2095 5.18277 2100 5.11631