Year Percent change (Units) 1983 3.947 1984 5.316 1985 12.500 1986 27.350 1987 2.517 1988 13.584 1989 4.035 1990 6.925 1991 13.831 1992 8.418 1993 -2.698 1994 7.580 1995 -0.032 1996 3.122 1997 1.979 1998 3.229 1999 4.436 2000 5.995 2001 6.638 2002 10.706 2003 12.250 2004 10.084 2005 8.651 2006 6.401 2007 5.675 2008 12.195 2009 1.228 2010 2.731 2011 7.084 2012 2.301 2013 0.187 2014 1.497 2015 0.184 2016 0.214 2017 9.792 2018 6.689 2019 -0.122 2020 -1.403 2021 6.911 2022 11.312 2023 7.344 2024 5.842 2025 3.279 2026 3.236 2027 3.310 2028 3.274 2029 3.262