Year Percent change (Units) 2001 -17.701 2002 -4.900 2003 13.839 2004 23.504 2005 4.302 2006 6.391 2007 8.007 2008 10.206 2009 2.578 2010 11.602 2011 15.359 2012 -1.948 2013 -2.032 2014 4.858 2015 -2.940 2016 7.591 2017 5.458 2018 10.897 2019 4.502 2020 -5.991 2021 31.427 2022 5.658 2023 6.921 2024 4.644 2025 4.654 2026 5.157 2027 4.493 2028 4.488 2029 4.046