Year Percent change (Units) 1993 54.039 1994 -13.774 1995 -15.735 1996 10.500 1997 -3.215 1998 -15.300 1999 -13.300 2000 3.532 2001 12.558 2002 5.892 2003 30.296 2004 13.575 2005 12.799 2006 12.308 2007 20.301 2008 13.492 2009 -41.623 2010 15.014 2011 21.517 2012 1.613 2013 -8.575 2014 -24.991 2015 -28.552 2016 8.279 2017 16.551 2018 8.495 2019 7.191 2020 -3.344 2021 17.040 2022 -24.734 2023 21.058 2024 10.989 2025 9.179 2026 9.339 2027 9.957 2028 4.344 2029 2.962