Year	Percent
1970	-27.17795
1971	-23.42843
1972	-20.93304
1973	-18.01398
1974	-26.43916
1975	-12.64032
1976	-11.07722
1977	-13.50531
1978	-6.97856
1979	-5.23014
1980	-5.47287
1981	-8.03483
1982	-14.96173
1983	-13.85234
1984	-14.05763
1985	-14.65213
1986	-9.48969
1987	-8.88749
1988	-9.50816
1989	-10.33407
1990	-12.81649
1991	-10.49388
1992	-6.94624
1993	-9.28107
1994	-9.77826
1995	-9.43089
1996	-9.36082
1997	-4.86267
1998	-2.63343
1999	-2.30242
2000	-7.1947
2001	-1.66479
2002	4.39711
2003	0.86971
2004	-1.32931
2005	-2.44453
2006	-3.37536
2007	0.56448
2008	-0.24801
2009	-1.5036
2010	-0.91068
2011	2.24669
2012	4.64382
2013	6.2776
2014	11.91768
2015	7.0607
2016	10.69811