Year	Percent
1972	0.00143
1973	0.02894
1974	0.01758
1975	0.00794
1976	0.05357
1977	0.07232
1978	0.05797
1979	-0.05146
1980	0.04692
1981	0.02647
1982	0.03757
1983	0.00229
1984	-0.00292
1985	-0.02989
1986	0.01119
1987	0.01319
1988	0.00692
1989	0.00086
1990	0.01025
1991	0.00449
1992	0.01174
1993	0.04236
1994	0.03301
1995	0.005
1996	0.02913
1997	0.2889
1998	0.38024
1999	0.35042
2000	0.52536
2001	0.14544
2002	0.09558
2003	0.44596
2004	0.68947
2005	1.09515
2006	0.63566
2007	0.81775
2008	1.44975
2009	0.87949
2010	1.06893
2011	0.98317
2012	1.1881
2013	1.73542
2014	1.46871
2015	1.45129
2016	1.05355
2017	0.8615