Year Percent change (Units) 1992 -82.872 1993 115.046 1994 -17.381 1995 24.539 1996 32.435 1997 -20.473 1998 -20.295 1999 -4.712 2000 -23.059 2001 32.500 2002 -16.993 2003 0.431 2004 13.292 2005 -0.781 2006 9.462 2007 38.382 2008 24.588 2009 15.812 2010 -5.717 2011 11.317 2012 9.802 2013 5.092 2014 1.727 2015 8.271 2016 0.035 2017 2.421 2018 40.346 2019 15.848 2020 -8.651 2021 -2.475 2022 8.262 2023 32.988 2024 10.775 2025 9.788 2026 9.702 2027 8.705 2028 8.175 2029 7.556