Year Percent 1989-01-01 12.5919000000000000 1990-01-01 10.6299000000000000 1991-01-01 9.1170300000000000 1992-01-01 7.0818699999999990 1993-01-01 4.9625699999999995 1994-01-01 2.7667000000000000 1995-01-01 1.6555300000000000 1996-01-01 0.9249530000000000 1997-01-01 0.4353890000000000 1998-01-01 10.2585000000000000 1999-01-01 13.4656000000000000 2000-01-01 13.1092000000000000 2001-01-01 15.4265000000000000 2002-01-01 21.4425000000000000 2003-01-01 20.3601000000000000 2004-01-01 21.0962000000000000 2005-01-01 19.8200000000000000 2006-01-01 21.9254000000000000 2007-01-01 23.5441000000000000 2008-01-01 19.7302000000000000 2009-01-01 24.8987000000000000 2010-01-01 25.0823000000000000 2011-01-01 22.2219000000000000 2012-01-01 25.0423000000000000 2013-01-01 24.6101000000000000 2014-01-01 25.9665000000000000 2015-01-01 27.2996000000000000 2016-01-01 27.8389000000000000