Year Percent change (Units) 2003 8.692 2004 0.671 2005 11.830 2006 5.361 2007 13.340 2008 3.863 2009 20.585 2010 8.438 2011 6.479 2012 13.968 2013 5.683 2014 2.697 2015 0.988 2016 2.164 2017 2.647 2018 1.189 2019 3.912 2020 -2.351 2021 -14.542 2022 -6.240