Year	Percent
1970	10.1235
1971	11.51932
1972	7.94734
1973	5.01223
1974	5.88399
1975	3.80559
1976	5.28531
1977	2.66169
1978	3.61654
1979	2.03878
1980	2.95937
1981	3.69108
1982	2.49987
1983	1.51613
1984	1.45942
1985	0.01605
1986	-0.30301
1987	0.69071
1988	1.39892
1989	3.44418
1990	2.15887
1991	3.19036
1992	3.27016
1993	8.12106
1994	10.43367
1995	5.60935
1996	6.17063
1997	17.41706
1998	12.07486
1999	9.44781
2000	8.33299
2001	9.46076
2002	11.18749
2003	7.14964
2004	7.51566
2005	5.87964
2006	4.80536
2007	3.83508
2008	10.04942
2009	3.69801
2010	2.47947
2011	0.16139
2012	-7.43221
2013	-4.25143
2014	2.43182
2015	0.72464
2016	-0.10573
2017	-1.91085