Year Percent 1992-01-01 10.195000000 1993-01-01 9.826296296 1994-01-01 17.032307690 1995-01-01 15.270000000 1996-01-01 16.470000000 1997-01-01 14.620000000 1998-01-01 14.550000000 1999-01-01 11.960000000 2000-01-01 8.660000000 2001-01-01 5.950000000 2002-01-01 9.640000000 2003-01-01 5.420000000 2004-01-01 4.080000000 2005-01-01 4.600000000 2006-01-01 5.120000000 2007-01-01 4.080000000 2008-01-01 2.540000000 2009-01-01 1.000000000 2010-01-01 2.020000000 2011-01-01 2.780000000 2012-01-01 2.020000000 2013-01-01 1.000000000 2014-01-01 0.260000000 2015-01-01 0.100000000 2016-01-01 0.100000000 2017-01-01 0.100000000