Year	Percent
1977	4.82783
1978	2.48273
1979	1.73049
1980	-11.56493
1981	4.32478
1982	4.2153
1983	-0.53517
1984	3.60922
1985	6.08388
1986	8.90624
1987	8.07947
1988	6.05872
1989	3.66809
1990	6.42594
1991	3.31417
1992	5.12044
1993	3.84363
1994	2.68833
1995	3.39478
1996	4.51343
1997	4.37242
1998	4.96122
1999	1.3146
2000	7.96048
2001	1.76638
2002	1.40686
2003	2.90944
2004	5.08471
2005	0.64371
2006	8.03321
2007	5.2465
2008	5.00654
2009	3.0411
2010	4.1292
2011	3.911
2012	3.2095
2013	3.13285
2014	3.5569
2015	3.33173
2016	3.72869
2017	3.70643