Year Percent change 1980 19.079 1981 10.858 1982 7.359 1983 10.244 1984 6.402 1985 10.649 1986 3.28 1987 -11.449 1988 4.105 1989 6.924 1990 21.276 1991 15.42 1992 19.358 1993 22.556 1994 42.557 1995 30.2 1996 20.584 1997 16.177 1998 12.722 1999 8.126 2000 11.459 2001 16.492 2002 9.345 2003 26.734 2004 28.316 2005 16.762 2006 14.21 2007 8.958 2008 14.381 2009 3.429 2010 4.136 2011 7.385 2012 6.78 2013 6.776 2014 3.944 2015 7.524 2016 13.378 2017 14.738 2018 13.478 2019 14.944 2020 12.953 2021 12.229 2022 11.448 2023 10.725 2024 10.225