Year Percent change (Units) 1993 929.867 1994 62.124 1995 30.959 1996 34.814 1997 12.979 1998 16.845 1999 39.837 2000 10.480 2001 3.685 2002 2.285 2003 5.565 2004 2.764 2005 4.921 2006 5.098 2007 20.094 2008 20.028 2009 -0.040 2010 19.226 2011 5.708 2012 7.495 2013 3.970 2014 10.475 2015 3.352 2016 -0.503 2017 3.656 2018 0.486 2019 3.056 2020 9.722 2021 11.195 2022 14.669 2023 7.275 2024 7.956 2025 5.536 2026 5.536 2027 4.000 2028 4.000 2029 4.000