Year	Percent
1992	-33.52998
1993	-40.94662
1994	-54.84245
1995	-60.54659
1996	-58.14998
1997	-56.18513
1998	-65.2586
1999	-77.19042
2000	-48.54012
2001	-50.44863
2002	-53.0278
2003	-61.12317
2004	-54.02011
2005	-48.7746
2006	-31.46183
2007	-23.01585
2008	-21.70344
2009	-18.91489
2010	-18.5563
2011	-8.77722