Year	Percent
1997-01-01	6.77883
1998-01-01	6.85527
1999-01-01	7.63333
2000-01-01	7.33846
2001-01-01	9.56199
2002-01-01	11.81250
2003-01-01	14.13570
2004-01-01	16.14910
2005-01-01	19.10850
2006-01-01	23.43070
2007-01-01	28.69550
2008-01-01	31.52450
2009-01-01	35.09770
2010-01-01	38.27270
2011-01-01	39.40090
2012-01-01	40.29540
2013-01-01	40.01660
2014-01-01	41.99380
2015-01-01	43.42200