Year	Percent
1978	4.95117
1979	8.08269
1980	8.899
1981	1.67738
1982	0.9771
1983	1.76946
1984	9.25911
1985	9.34064
1986	11.42164
1987	7.23923
1988	10.32007
1989	6.15019
1990	4.93706
1991	-2.57543
1992	3.39992
1993	5.76517
1994	4.00336
1995	4.47563
1996	4.70946
1997	5.74316
1998	-1.72302
1999	2.21908
2000	9.35254
2001	4.05118
2002	1.15036
2003	-4.97012
2004	2.17042
2005	7.33938
2006	0.57274
2007	-1.3255
2008	5.13253
2009	-4.07587
2010	-3.31126
2011	1.29413
2012	-1.70623
2013	5.06518
2014	4.83913
2015	2.92487
2016	1.21539
2017	0.7798