Year	Percent
1997	1.2827
1998	1.0024
1999	1.4541
2000	1.7169
2001	2.9192
2002	2.632
2003	2.8268
2004	4.7854
2005	3.4003
2006	3.8479
2007	3.4716
2008	3.7533
2009	4.0008
2010	4.5
2011	5.3554
2012	4.5498
2013	4.6365
2014	4.1031
2015	4.8028
2016	3.8709
2017	3.7306