Year Percent change 1980 -10.06 1981 5.882 1982 5.497 1983 0.384 1984 4.775 1985 6.876 1986 9.742 1987 10.163 1988 6.791 1989 4.465 1990 7.187 1991 4.435 1992 6.513 1993 5.082 1994 4.136 1995 4.288 1996 5.588 1997 5.687 1998 6.072 1999 2.611 2000 8.192 2001 3.214 2002 1.627 2003 5.984 2004 4.299 2005 1.453 2006 4.514 2007 5.727 2008 5.387 2009 3.315 2010 4.377 2011 4.077 2012 3.496 2013 3.36 2014 3.745 2015 3.553 2016 3.838 2017 3.809 2018 3.76 2019 3.86 2020 3.93 2021 4.011 2022 4.011 2023 4.011 2024 4.011