Year Percent change (Units) 1996 23.092 1997 8.735 1998 5.369 1999 1.443 2000 1.094 2001 1.549 2002 0.336 2003 -1.077 2004 1.154 2005 2.672 2006 3.757 2007 5.818 2008 11.092 2009 4.161 2010 1.191 2011 4.124 2012 3.164 2013 1.164 2014 0.242 2015 -0.677 2016 0.678 2017 3.718 2018 2.531 2019 2.242 2020 1.062 2021 4.625 2022 18.858 2023 8.685 2024 1.460 2025 2.330 2026 2.243 2027 2.276 2028 2.298 2029 2.322