Year	Percent
1992	3.87169
1993	3.97073
1994	4.17511
1995	3.73562
1996	3.44399
1997	3.43376
1998	3.09597
1999	3.49032
2000	5.20959
2001	6.18254
2002	6.76208
2003	6.57201
2004	6.39657
2005	6.10634
2006	4.53597
2007	2.955
2008	1.69521
2009	1.88778
2010	2.32413
2011	2.54388
2012	2.78479
2013	2.9544
2014	2.55783
2015	1.96868
2016	1.47153
2017	1.07242