Year Percent change (Units) 1993 -7.500 1994 -1.800 1995 -1.100 1996 1.200 1997 1.351 1998 3.381 1999 4.348 2000 4.539 2001 -3.067 2002 1.494 2003 2.223 2004 4.674 2005 4.724 2006 5.137 2007 6.473 2008 5.472 2009 -0.359 2010 3.359 2011 2.340 2012 -0.456 2013 2.925 2014 3.629 2015 3.856 2016 2.848 2017 1.082 2018 2.881 2019 3.910 2020 -4.688 2021 4.511 2022 2.221 2023 1.027 2024 2.700 2025 3.700 2026 3.900 2027 3.900 2028 3.800 2029 3.500