Year Percent change (Units) 2001 -1.519 2002 12.869 2003 29.196 2004 9.720 2005 11.708 2006 7.347 2007 17.289 2008 4.882 2009 -5.583 2010 12.054 2011 3.569 2012 -0.073 2013 17.901 2014 4.222 2015 10.832 2016 11.317 2017 9.767 2018 7.876 2019 10.090 2020 -5.008 2021 13.881 2022 12.379 2023 8.927 2024 6.075 2025 6.738 2026 5.673 2027 5.514 2028 5.395 2029 5.570