Year	Percent
1979	0.99737
1980	3.02138
1981	2.93307
1982	3.08436
1983	2.84445
1984	1.97915
1985	1.89905
1986	0.62258
1987	1.37187
1988	2.84715
1989	0.74103
1990	6.8737
1991	0.37219
1992	6.76284
1993	5.57614
1994	3.70073
1995	3.52946
1996	0.11379
1997	0.74428
1998	6.45861
1999	-1.70965
2000	0.03511
2001	2.4879
2002	1.66466
2003	1.74072
2004	9.18856
2005	6.15052
2006	14.83991
2007	11.09938
2008	9.60842
2009	5.59634
2010	11.34073
2011	10.65977
2012	9.46594
2013	6.31742
2014	7.76179
2015	7.05799
2016	6.03326
2017	5.93647