Year Percent 1950 13.33762 1955 13.76175 1960 13.95018 1965 14.1794 1970 14.5145 1975 14.61941 1980 15.13271 1985 14.92335 1990 16.21498 1995 15.63911 2000 14.33948 2005 12.34988 2010 10.97567 2015 9.96954 2020 9.36953 2025 9.35293 2030 8.43329 2035 7.36759 2040 6.6183 2045 6.22062 2050 6.09591 2055 6.03108 2060 5.84523 2065 5.55114 2070 5.26373 2075 5.09801 2080 5.0642 2085 5.08098 2090 5.05921 2095 4.97247 2100 4.85862