Year	Percent
1983	-80.93897
2004	-61.5228
2005	-58.25636
2006	-58.28884
2007	-53.08493
2008	-61.0398
2009	-63.78764
2010	-57.47917
2011	-57.54663
2012	-51.78107
2013	-52.83016
2014	-47.32235
2015	-51.21341
2016	-45.7841
