Year Percent change (Units) 1998 8.895 1999 5.827 2000 26.654 2001 11.266 2002 25.071 2003 31.477 2004 26.920 2005 24.338 2006 26.019 2007 21.128 2008 10.836 2009 -10.560 2010 28.461 2011 10.964 2012 5.882 2013 8.760 2014 4.295 2015 -2.156 2016 0.679 2017 6.954 2018 4.249 2019 1.957 2020 -3.150 2021 18.517 2022 -0.166 2023 -0.319 2024 2.518 2025 2.000 2026 3.000 2027 3.000 2028 3.000 2029 3.000