Year Percent change (Units) 1980 0.345 1981 3.437 1982 -6.901 1983 0.900 1984 2.700 1985 3.300 1986 5.230 1987 13.370 1988 21.446 1989 8.957 1990 4.489 1991 4.416 1992 -1.643 1993 4.004 1994 18.287 1995 2.991 1996 -2.406 1997 10.088 1998 6.339 1999 6.701 2000 7.313 2001 15.678 2002 1.907 2003 7.213 2004 15.231 2005 1.491 2006 6.345 2007 17.699 2008 -2.585 2009 -2.161 2010 6.507 2011 -3.939 2012 1.634 2013 -0.732 2014 -2.936 2015 -2.818 2016 2.021 2017 3.209 2018 3.473 2019 -5.056 2020 -10.958 2021 12.380 2022 13.896 2023 9.230 2024 0.523 2025 1.417 2026 1.783 2027 1.783 2028 1.621 2029 1.300