Year Percent 1982-01-01 0.533743000000000100 1983-01-01 0.360406000000000000 1984-01-01 0.317626000000000000 1985-01-01 0.277028000000000000 1986-01-01 0.357719000000000000 1987-01-01 0.204642000000000020 1988-01-01 0.055885000000000004 1989-01-01 0.074906000000000000 1990-01-01 0.128032999999999980 1991-01-01 0.135841000000000020 1992-01-01 0.122368000000000000 1993-01-01 0.085781000000000000 1994-01-01 5.516400000000000000 1995-01-01 5.283720000000000000 1996-01-01 5.298369999999999000 1997-01-01 5.631550000000000000 1998-01-01 5.116680000000001000 1999-01-01 8.041630000000000000 2000-01-01 8.521310000000000000 2001-01-01 8.769039999999999000 2002-01-01 9.864090000000000000 2003-01-01 10.050100000000000000 2004-01-01 8.710960000000000000 2005-01-01 6.705010000000001000 2006-01-01 4.664400000000000000 2007-01-01 3.670069999999999500 2008-01-01 2.821059999999999700 2009-01-01 3.097010000000000000 2010-01-01 2.290170000000000300 2011-01-01 1.911720000000000000 2012-01-01 2.092580000000000000 2013-01-01 2.285850000000000000 2014-01-01 2.333409999999999800 2015-01-01 2.571150000000000000 2016-01-01 2.787570000000000000