Year Percent change (Units) 1993 -11.894 1994 16.143 1995 29.324 1996 13.534 1997 15.769 1998 19.343 1999 -2.700 2000 2.675 2001 15.639 2002 2.711 2003 11.865 2004 20.656 2005 17.055 2006 21.879 2007 17.446 2008 -11.140 2009 -30.894 2010 12.806 2011 22.780 2012 5.247 2013 -0.127 2014 3.000 2015 1.647 2016 3.565 2017 8.546 2018 6.338 2019 2.224 2020 -1.143 2021 15.061 2022 11.094 2023 -2.857 2024 3.000 2025 2.500 2026 2.500 2027 2.500 2028 2.500 2029 2.500