Year	Percent
1967	7.36115
1968	7.32899
1969	5.92404
1970	2.42976
1971	3.36783
1972	0.33016
1973	1.43556
1974	3.37626
1975	5.2031
1976	8.28284
1977	3.55861
1978	-0.23189
1979	2.24318
1980	1.12094
1981	-4.12914
1982	6.32297
1983	-1.02659
1984	3.95861
1985	3.65179
1986	6.95155
1987	-2.3471
1988	9.69305
1989	0.89742
1990	1.49523
1991	5.26628
1992	-3.83574
1993	-2.44082
1994	8.79012
1995	-6.8472
1996	10.77656
1997	-2.87105
1998	5.88347
1999	-0.157
2000	0.68131
2001	6.03023
2002	1.88881
2003	4.70124
2004	3.5606
2005	2.08217
2006	6.32752
2007	2.33452
2008	4.6766
2009	2.9643
2010	2.47115
2011	3.80474
2012	1.53897
2013	3.01271
2014	1.18559
2015	3.08033
2016	-0.15111
2017	2.73274