Year	Percent
1970	2.00823
1971	0.83564
1972	1.16978
1973	0.69393
1974	-0.42245
1975	0.27919
1976	0.35114
1977	0.41678
1978	0.08111
1979	0.30079
1980	0.30717
1981	0.1619
1982	-0.00096
1983	0.00096
1984	0.00109
1985	-0.00861
1986	0.08233
1987	0.0064
1988	0
1989	4.13342
1990	3.18255
1991	6.08027
1992	4.57565
1993	0.06172
1994	0.85408
1995	0.61437
1996	1.50426
1997	1.19099
1998	1.54586
1999	1.45975
2000	-0.49677
2001	0.62401
2002	-0.63199
2003	0.27179
2004	-0.90019
2005	-0.18289
2006	-0.24021
2007	2.32859
2008	0.67318
2009	-0.26394
2010	0.7669
2011	2.06155
2012	3.4537
2013	3.9339
2014	4.1741
2015	1.80484
2016	1.53603
2017	1.988