Year	Percent
1988	1.19
1990	0.84
1995	2.4
1997	3.29
1998	2.77
2000	3.58
2002	4.27
2004	4.43
2006	0.46
2007	0.26
2008	0.22
2009	0.34
2010	0.44
2011	0.5
2013	1.83
2014	1.14
2015	2.23
2018	2.46