Year	Percent
1989	-73.21726
1990	-81.91118
1991	-71.00775
1992	-64.48019
1993	-61.12736
1994	-54.5309
1995	-51.52248
1996	-42.40397
1997	-33.02268
1998	-27.19033
1999	-22.68619
2000	-21.76018
2001	-24.34698
2002	-18.84525
2003	-20.61767
2004	-22.07977
2005	-20.73479
2006	-21.29466
2007	-24.83401
2008	-29.01155
2009	-23.50604
2010	-24.4415
2011	-27.24343
2012	-26.59696
2013	-26.69541
2014	-26.30435
2015	-20.28226
2016	-21.6248
2017	-22.76547