Year	Percent
1996-01-01	0.24
1997-01-01	0.85
1998-01-01	1.52
1999-01-01	2.52
2000-01-01	3.68
2001-01-01	5.55
2002-01-01	8.40
2003-01-01	10.62
2004-01-01	11.26
2005-01-01	11.81
2006-01-01	13.39
2007-01-01	13.27
2008-01-01	10.99
2009-01-01	14.02
2010-01-01	16.64
2011-01-01	16.68
2012-01-01	18.90
2013-01-01	19.07
2014-01-01	20.04
2015-01-01	21.78
2016-01-01	22.97