Year	Percent
1998-01-01	11.22358412935650
1999-01-01	12.09605261639440
2000-01-01	11.35193539593520
2001-01-01	10.79246219864540
2002-01-01	10.35682332959200
2003-01-01	9.79346320219682
2004-01-01	10.59146466367650
2005-01-01	9.99496896390365
2006-01-01	9.00878498974289
2007-01-01	8.39729788056662
2008-01-01	7.76076080561870
2009-01-01	9.61590277346204
2010-01-01	12.71716374256030
2011-01-01	17.87071069696170
2012-01-01	24.44173634087230
2013-01-01	27.46715096533280
2014-01-01	26.49027497452220
2015-01-01	24.90084099327110
2016-01-01	23.54104258985110
2017-01-01	21.48901282588200