Year	Percent
1988	8.27257
1989	-6.71105
1990	31.77945
1991	-7.25421
1992	-17.37883
1993	-1.30768
1994	-19.39615
1995	-9.24536
1996	4.72136
1997	-12.77871
1998	5.68373
1999	15.12648
2000	4.30139
2001	3.24764
2002	-0.74152
2003	2.25429
2004	3.93649
2005	11.82207
2006	9.68756
2007	9.69032
2008	13.17497
2009	4.5706
2010	7.49864
2011	12.77466
2012	9.1222
2013	8.17851
2014	8.28289
2015	4.60466
2016	4.37591
2017	4.73308