Year Percent change (Units) 1993 1662.275 1994 1401.987 1995 176.379 1996 39.180 1997 17.401 1998 7.132 1999 8.323 2000 13.154 2001 8.373 2002 5.853 2003 6.447 2004 6.868 2005 7.521 2006 8.583 2007 10.779 2008 17.148 2009 7.300 2010 7.125 2011 8.354 2012 5.118 2013 5.829 2014 6.717 2015 6.651 2016 14.556 2017 7.429 2018 6.025 2019 5.244 2020 6.799 2021 8.002 2022 14.956 2023 14.558 2024 8.671 2025 6.975 2026 6.121 2027 5.373 2028 5.058 2029 5.000