Year	Percent
1983	1.9251
1987	2.6394
1988	1.957
1989	2.334
1991	2.7473
1996	2.8807
2006	2.3151
2007	1.4172
2008	1.8697
2009	2.3777
2010	2.6044
2011	1.5314
2012	1.7614
2013	4.6761
2014	5.937
2015	2.6519
2016	3.4334
2017	2.2108