Year Percent 1963-01-01 10.22740000000000000 1964-01-01 9.89983000000000000 1965-01-01 10.67910000000000000 1966-01-01 10.00230000000000000 1967-01-01 9.16551000000000100 1968-01-01 9.60397000000000000 1969-01-01 11.09480000000000000 1970-01-01 11.90790000000000000 1971-01-01 13.39010000000000000 1972-01-01 15.16730000000000000 1973-01-01 16.62760000000000000 1974-01-01 14.32500000000000000 1975-01-01 15.50410000000000000 1976-01-01 16.45270000000000000 1977-01-01 19.53599999999999800 1978-01-01 23.61030000000000000 1979-01-01 24.50200000000000000 1980-01-01 25.92310000000000000 1981-01-01 29.29970000000000000 1982-01-01 33.50780000000000000 1983-01-01 36.01690000000000000 1984-01-01 26.89520000000000000 1985-01-01 25.73590000000000000 1986-01-01 25.23390000000000000 1987-01-01 20.27490000000000000 1988-01-01 17.63440000000000000 1989-01-01 11.45990000000000000 1990-01-01 8.64513000000000000 1991-01-01 8.30928000000000100 1992-01-01 8.14218000000000000 1993-01-01 7.13435000000000000 1994-01-01 4.76374000000000000 1995-01-01 3.47371000000000000 1996-01-01 1.65268000000000000 1997-01-01 1.63943000000000000 1998-01-01 1.95419000000000000 1999-01-01 2.15467000000000000 2000-01-01 2.09867000000000030 2001-01-01 1.35509000000000000 2002-01-01 0.48510400000000000 2003-01-01 0.37564899999999996 2004-01-01 0.35333100000000000 2005-01-01 0.39237200000000000 2006-01-01 0.48771700000000000 2007-01-01 0.88446100000000000 2008-01-01 0.70656400000000010 2009-01-01 0.72509000000000000 2010-01-01 0.37416100000000000