Year	Percent
1970	0.41852
1971	-0.76416
1972	0.12117
1973	0.10567
1974	0.67329
1975	2.15085
1976	0.92897
1977	0.995
1978	2.40412
1979	2.21824
1980	1.95811
1981	-0.28157
1982	1.39849
1983	0.06738
1984	0.09898
1985	-0.65127
1986	0.92417
1987	0.66354
1988	0.30286
1989	0.03495
1990	1.64525
1991	0.65109
1992	2.40471
1993	-2.13816
1994	-0.72024
1995	0.38219
1996	0.49673
1997	0.98457
1998	-0.0493
1999	0.01368
2000	0.87457
2001	1.1601
2002	0.35894
2003	0.67685
2004	0.79818
2005	1.46055
2006	1.10439
2007	2.30563
2008	5.21777
2009	11.69657
2010	13.91706
2011	16.62914
2012	12.11827
2013	9.37844
2014	9.98662
2015	7.29886
2016	3.95869
2017	4.11748