Year Percent change (Units) 1980 0.000 1981 0.000 1982 0.000 1983 0.000 1984 0.000 1985 0.000 1986 0.000 1987 0.000 1988 0.000 1989 0.000 1990 0.000 1991 6.066 1992 -7.680 1993 4.389 1994 -3.010 1995 10.351 1996 -6.388 1997 -1.554 1998 -24.945 1999 40.284 2000 10.683 2001 -20.894 2002 7.101 2003 4.871 2004 8.904 2005 3.347 2006 8.186 2007 12.815 2008 3.403 2009 -10.646 2010 4.818 2011 5.842 2012 0.416 2013 3.329 2014 4.893 2015 7.785 2016 2.213 2017 5.837 2018 4.441 2019 3.872 2020 -6.830 2021 10.282 2022 6.294 2023 -0.208 2024 1.952 2025 3.701 2026 3.725 2027 3.640 2028 3.935 2029 3.919