Year Percent change (Units) 1996 17.380 1997 9.567 1998 50.806 1999 34.147 2000 8.044 2001 16.440 2002 12.623 2003 5.132 2004 6.068 2005 5.200 2006 10.719 2007 -10.192 2008 -8.188 2009 11.207 2010 5.471 2011 15.417 2012 11.039 2013 18.456 2014 14.802 2015 21.497 2016 13.567 2017 6.843 2018 13.656 2019 18.018 2020 -3.381 2021 23.673 2022 -7.191 2023 -11.497 2024 10.333 2025 8.330 2026 7.376 2027 7.377 2028 7.277 2029 6.819