Year	Percent
1970	0.15837
1971	0.19941
1972	0.25078
1973	0.06671
1974	0.14075
1975	0.23147
1976	0.18192
1977	0.14336
1978	0.09315
1979	0.06186
1980	0.05206
1981	0.18986
1982	0.00172
1983	0.16558
1984	0.25731
1985	0.20122
1986	0.47246
1987	0.28887
1988	0.48738
1989	0.41169
1990	0.5739
1991	-0.18215
1992	0.35194
1993	0.96747
1994	1.44768
1995	0.77804
1996	0.84652
1997	1.67819
1998	8.98085
1999	3.43808
2000	10.75309
2001	2.49302
2002	5.79062
2003	3.48601
2004	3.44125
2005	5.31992
2006	2.13879
2007	8.60861
2008	6.8383
2009	-3.50956
2010	4.934
2011	-2.19537
2012	1.92159
2013	-1.83003
2014	6.32539
2015	7.2455
2016	1.88705
2017	4.30798