Year	Percent
1983	5.7955
1984	5.7099
1985	4.5919
1986	5.6785
1987	5.0303
1988	6.0705
1989	3.8542
1990	3.1177
1991	2.3619
1992	2.3615
1993	3.51
1994	4.5048
1995	3.7844
1996	4.6738
1997	4.8169
1998	5.2804
1999	4.5411
2000	3.393
2001	3.9201
2002	3.3119
2003	1.8455
2004	4.0642
2005	3.8498
2006	4.2321
2007	3.5518
2008	3.5982
2009	5.0253
2010	4.228
2011	3.8767
2012	4.0604
2013	5.4662
2014	5.5544
2015	6.3308
2016	5.3662
2017	5.3177