Year Percent change (Units) 1993 874.255 1994 307.547 1995 197.300 1996 47.752 1997 14.761 1998 27.686 1999 85.746 2000 20.799 2001 21.477 2002 15.789 2003 13.663 2004 10.889 2005 12.685 2006 9.669 2007 9.007 2008 14.111 2009 11.647 2010 6.849 2011 8.440 2012 5.075 2013 6.754 2014 7.823 2015 15.534 2016 7.042 2017 3.683 2018 2.878 2019 4.470 2020 3.382 2021 6.694 2022 13.750 2023 5.859 2024 6.870 2025 4.548 2026 4.000 2027 4.000 2028 4.000 2029 4.000