Year Percent change (Units) 2001 -18.305 2002 -7.422 2003 5.883 2004 15.149 2005 5.554 2006 7.665 2007 12.079 2008 14.217 2009 0.246 2010 8.678 2011 16.379 2012 -0.840 2013 -0.774 2014 0.887 2015 -4.804 2016 9.622 2017 5.671 2018 7.013 2019 4.522 2020 -3.664 2021 28.882 2022 2.244 2023 6.379 2024 4.902 2025 5.334 2026 5.645 2027 5.072 2028 5.127 2029 4.667