Year	Percent
1998	9.89
1999	10.18
2000	9.41
2001	10.62
2002	10.13
2003	9.76
2004	8.61
2005	9.12
2006	9.53
2007	9.46
2008	9.35
2009	9.12
2010	8.75
2011	8.62
2012	8.26
2013	7.75
2014	7.99
2016	5.87
2017	4.33