Year Percent change (Units) 1980 9.657 1981 19.719 1982 22.937 1983 10.090 1984 -6.409 1986 5.575 1987 -9.705 1988 -18.206 1989 -4.637 1990 4.453 1991 -0.245 1992 -8.784 1993 -5.915 1994 2.885 1995 -2.346 1996 10.215 1997 16.728 1998 9.300 1999 -0.200 2000 6.694 2001 12.368 2002 0.690 2003 -1.377 2004 3.690 2005 5.780 2006 3.317 2007 18.242 2008 11.525 2009 -12.502 2010 -3.021 2011 9.142 2012 4.507 2013 8.426 2014 10.312 2015 2.895 2016 -0.746 2017 1.186 2018 2.055 2019 22.782 2020 -15.623 2021 14.881 2022 -11.784 2023 13.326 2024 5.686 2025 6.359 2026 5.568 2027 4.451 2028 5.142 2029 6.030