Year	Percent
1971	6.68837
1972	3.02246
1973	1.73518
1974	-0.52584
1975	8.04895
1976	4.25895
1977	7.6894
1978	5.75398
1979	0.40686
1980	-5.40947
1981	19.09456
1982	8.46382
1983	4.97668
1984	7.38747
1985	0.93236
1986	-0.74241
1987	-3.3666
1988	2.60668
1989	-0.34684
1990	-3.82508
1991	-11.37529
1992	-12.15542
1993	-15.35742
1994	0.19295
1995	1.9362
1996	7.29794
1997	2.2891
1998	-0.29452
1999	5.74998
2000	5.52787
2001	2.85475
2002	1.14042
2003	3.54457
2004	5.56348
2005	11.03105
2006	11.94701
2007	7.19141
2008	4.06098
2009	1.372
2010	2.25981
2011	2.60674
2012	2.76605
2013	2.47731
2014	0.80379
2015	4.24092