Year	Percent
1975	2.52197
1976	-0.66037
1977	0.60254
1978	0.26475
1979	-0.06965
1980	0.35094
1981	0.38517
1982	0.40387
1983	0.05915
1984	0.04533
1985	0.12432
1986	0.07508
1987	0.09261
1988	0.09619
1989	0.28562
1990	0.25131
1991	0.30319
1992	0.3508
1993	2.09512
1994	4.2795
1995	1.6473
1996	1.73036
1997	1.187
1998	2.23768
1999	3.157
2000	3.3293
2001	1.68056
2002	0.95567
2003	1.79172
2004	1.56811
2005	1.35087
2006	3.11622
2007	5.58661
2008	9.51704
2009	9.13294
2010	7.85507
2011	8.20797
2012	7.85537
2013	6.75033
2014	8.60496
2015	8.54969
2016	8.14262
2017	6.87722