Year	Percent
1983	1.813
1984	1.8885
1991	2.5573
2003	2.4115
2004	1.9818
2005	0.8519
2006	2.4845
2007	1.7196
2008	3.0475
2009	4.0055
2010	2.1729
2011	2.3534
2012	2.4803
2013	5.2559
2014	4.1572
2015	3.7666
2016	4.1896
2017	3.5454