Year	Percent
2006	-35.1955
2007	-35.18115
2008	-38.58531
2009	-34.87622
2010	-35.56984
2011	-33.26127
2012	-29.10399
2013	-27.69488
2014	-28.71486
2015	-28.45236
2016	-27.62074
2017	-26.77047