Year	Percent
1980	6.6162
1981	7.45001
1982	-1.64752
1983	1.80991
1984	12.16644
1985	-3.44065
1986	-2.97489
1987	16.45543
1988	9.81153
1989	6.45174
1990	-0.99691
1991	10.29543
1992	2.77853
1993	2.0485
1994	2.34613
1995	1.71353
1996	2.07728
1997	3.17786
1998	8.1571
1999	3.07515
2000	2.18459
2001	3.72253
2002	2.7828
2003	0.78844
2004	2.12213
2005	0.4219
2006	3.87272
2007	5.47254
2008	7.32286
2009	2.31127
2010	2.61735
2011	3.09892
2012	0.41371
2013	2.65712
2014	1.98405
2015	2.48453
2016	2.18742
2017	2.5721