Year Percent change (Units) 1980 -1.780 1981 8.024 1982 -7.188 1983 -5.250 1984 4.451 1985 -2.522 1986 -19.269 1987 5.304 1988 -2.623 1989 15.733 1990 23.562 1991 2.176 1992 3.144 1993 0.262 1994 7.449 1995 6.629 1996 5.399 1997 8.567 1998 0.878 1999 3.830 2000 12.322 2001 1.399 2002 2.433 2003 8.801 2004 9.566 2005 4.855 2006 9.837 2007 3.184 2008 3.192 2009 -5.243 2010 5.284 2011 6.216 2012 1.824 2013 5.056 2014 4.166 2015 6.787 2016 5.561 2017 0.735 2018 1.314 2019 1.108 2020 -4.957 2021 4.355 2022 7.850 2023 3.404 2024 3.515 2025 4.171 2026 4.267 2027 4.363 2028 4.461 2029 4.543