Year Percent change (Units) 1996 11.746 1997 8.542 1998 3.081 1999 0.385 2000 1.665 2001 2.030 2002 -0.895 2003 -1.305 2004 2.847 2005 2.994 2006 4.553 2007 8.198 2008 8.462 2009 1.174 2010 3.624 2011 3.475 2012 2.916 2013 0.530 2014 -0.189 2015 -0.249 2016 1.960 2017 3.806 2018 1.758 2019 2.730 2020 -0.072 2021 10.702 2022 19.980 2023 0.633 2024 1.787 2025 2.190 2026 2.370 2027 2.505 2028 2.141 2029 2.344