Year	Percent
1986	3.3259
1987	1.7099
1988	1.4688
1989	1.4199
1990	0.9365
1991	1.6594
1992	3.0087
1993	2.1059
1994	1.4766
1995	1.8249
1999	1.5793
2003	1.3678
2004	1.5993
2005	1.7255
2006	1.5904
2007	1.0902
2008	1.3772
2009	2.9848
2010	3.4175
2011	1.5889
2012	3.9564
2013	6.4231
2014	4.4499
2015	4.1219
2016	3.3112
2017	3.9452