Year	Percent
1988	-1.30708
1989	1.38053
1990	3.97969
1991	90.72728
1992	712.14926
1993	1078.88285
1994	1238.59527
1995	370.94395
1996	81.55525
1997	66.08707
1998	38.99796
1999	44.11536
2000	47.34079
2001	45.18965
2002	45.44937
2003	26.72341
2004	15.72053
2005	21.37413
2006	23.64004
2007	21.40013
2008	26.82551
2009	17.20834
2010	16.45577
2011	16.57281
2012	14.90966
2013	14.27509
2014	11.94871
2015	9.07486
2016	7.37692
2017	18.96931