Year	Percent change (Units)
2003	49.526
2004	-8.443
2005	41.964
2006	-6.922
2007	-11.906
2008	-6.741
2009	30.006
2010	11.252
2011	1.999
2012	-19.357
2013	-40.137
2014	51.946
2015	-10.213
2016	-15.971
2017	-6.170
2018	28.021
2019	-3.302
2020	0.534