Year	Percent
1998	1.51
1999	1.51
2000	1.46
2001	1.38
2002	1.09
2003	1.36
2004	1.56
2005	1.31
2006	2.02
2007	1.77
2008	1.57
2009	1.72
2010	1.28
2011	1.29
2012	1.23
2013	1.13
2014	0.95
2015	0.87
2016	0.84
2017	0.77
