Year Percent change 1981 3.108 1982 18.428 1983 1.792 1984 5.924 1985 -1.898 1986 2.362 1987 2.895 1988 2.293 1989 0.728 1990 6.048 1991 21.408 1992 14.495 1993 7.536 1994 42.351 1995 40.7 1996 8.743 1997 16.606 1998 -5.956 1999 1.967 2000 5.924 2001 -0.219 2002 6.165 2003 7.677 2004 10.25 2005 5.608 2006 12.138 2007 6.579 2008 22.323 2009 5.737 2010 0.227 2011 8.336 2012 3.885 2013 3.645 2014 2.114 2015 4.531 2016 7.284 2017 0.665 2018 1.135 2019 5 2020 5 2021 5 2022 5 2023 5 2024 5