Year Percent change (Units) 2001 -7.656 2002 13.231 2003 31.648 2004 5.726 2005 14.442 2006 4.919 2007 17.205 2008 4.218 2009 -8.816 2010 16.825 2011 3.646 2012 -0.836 2013 21.909 2014 1.668 2015 9.614 2016 12.662 2017 8.470 2018 5.699 2019 8.449 2020 -2.447 2021 14.689 2022 9.462 2023 4.765 2024 6.066 2025 6.976 2026 5.662 2027 5.724 2028 5.563 2029 5.843