Year Percent change 1993 -2.3 1994 -5.2 1995 -0.9 1996 1.7 1997 5.2 1998 4.3 1999 4.3 2000 3.8 2001 4.2 2002 4 2003 4.2 2004 7.4 2005 7 2006 7.5 2007 9.5 2008 9 2009 8.1 2010 8.475 2011 8.281 2012 8.18 2013 8.026 2014 8.008 2015 7.872 2016 9.013 2017 8.868 2018 5 2019 5 2020 5.5 2021 6 2022 6 2023 6 2024 6