Year	Percent
1977	0.71589
1978	2.14255
1979	6.7013
1980	2.39295
1981	3.21537
1982	1.14711
1983	1.74146
1984	2.37949
1985	3.3946
1986	3.39303
1987	2.33958
1988	3.39567
1989	3.15317
1990	1.70182
1991	0.68433
1992	1.09662
1993	1.05843
1994	2.42013
1995	0.99403
1996	0.94041
1997	1.13538
1998	1.26844
1999	1.17439
2000	1.237
2001	0.52227
2002	0.73636
2003	0.28628
2004	1.58957
2005	5.99382
2006	9.34353
2007	8.87354
2008	5.83141
2009	3.55144
2010	2.91729
2011	-0.20453
2012	1.00142
2013	1.45267
2014	1.50958
2015	2.08153
2016	2.435
2017	3.14047