Year	Percent
1989	14.66
1997	15.49
1999	14.75
2000	14.55
2001	14.01
2002	14.14
2003	13.91
2005	12.0589
2006	11.539
2007	11.335
2008	11.1496
2009	11.2694
2010	10.8893
2011	15.0407
2012	14.6347
2013	13.2624
2015	12.4688
2016	12.4531
2017	12.393