Year Percent change (Units) 2001 10.126 2002 -0.408 2003 -9.942 2004 -5.148 2005 2.758 2006 -16.253 2007 2.392 2008 10.097 2009 3.638 2010 8.422 2011 11.136 2012 -0.186 2013 -12.587 2014 -2.876 2015 7.316 2016 -8.954 2017 6.232 2018 31.608 2019 -16.875 2020 -2.512 2021 21.808 2022 20.904 2023 -12.452 2024 -1.816 2025 1.674 2026 2.200 2027 2.600 2028 2.600 2029 2.600