Year	Percent
1988	6.50068
1989	0.62534
1990	-1.02978
1991	-2.5912
1992	-13.25761
1993	-4.49516
1994	-7.04287
1995	-2.67454
1996	-0.22672
1997	3.23531
1998	2.63474
1999	3.18178
2000	2.37356
2001	2.88918
2002	2.73497
2003	2.99448
2004	6.46453
2005	5.76243
2006	5.99866
2007	8.36754
2008	7.26416
2009	6.29129
2010	5.48003
2011	5.43187
2012	6.61885
2013	6.32625
2014	5.98942
2015	6.13254
2016	5.94172
2017	3.54658