Year	Percent
1970	13.31867
1971	5.64119
1978	1.46735
1979	-0.03294
1981	-1.03681
1984	-1.75439
1985	1.76907
1986	2.01887
1987	2.47695
1988	4.44586
1989	5.13562
1990	4.16414
1991	3.0581
1992	3.01019
1993	1.64327
1994	2.64597
1995	3.39439
1996	2.58504
1997	1.8271
1998	2.56171
1999	7.31222
2000	3.55313
2001	7.01659
2002	2.73027
2003	-1.10309
2004	10.53993
2005	11.38987
2006	8.93893
2007	10.87685
2008	12.397
2009	8.14088
2010	6.90351
2011	6.41212
2012	12.34067
2013	5.72053
2014	8.28058
2015	3.32398
2016	1.79838
2017	1.39484