Year	Percent
1977	-4.20567
1978	3.02603
1979	5.35455
1980	-16.22313
1981	-18.81642
1982	-32.99481
1983	-12.727
1984	-8.54416
1985	-14.74263
1986	-30.15092
1987	-22.58747
1988	-4.58413
1989	-10.93315
1990	1.03179
1991	2.48961
1992	4.16821
1993	7.62094
1994	2.46566
1995	-6.46454
1996	-10.23218
1997	-5.14239
1998	-3.30039
1999	-7.3731
2000	-3.80646
2001	-5.1501
2002	-5.71734
2003	-8.42796
2004	-6.34697
2005	-13.44671
2006	-23.35714
2007	-26.77158
2008	-23.88423
2009	-11.832
2010	-13.45771
2011	-9.07251
2012	-13.09626
2013	-14.68931
2014	-11.86219
2015	-4.99836
2016	-5.32911