Year	Percent
1988	1.9
1990	1.84
1995	1.57
1997	1.86
1998	1.71
2000	2.61
2002	3.12
2004	3.5
2006	0.5144
2007	0.2862
2008	0.2166
2009	0.3581
2010	0.4206
2011	0.5279
2013	1.5503
2014	1.0639
2015	1.3283