Year Percent change (Units) 1985 1.102 1986 2.452 1987 1.258 1988 1.295 1989 0.541 1990 2.470 1991 2.752 1992 2.900 1993 1.358 1994 4.545 1995 4.791 1996 1.101 1997 1.424 1998 -0.743 1999 0.357 2000 1.302 2001 -3.110 2002 -0.253 2003 1.943 2004 0.894 2005 1.105 2006 -0.319 2007 1.938 2008 1.882 2009 0.529 2010 0.185 2011 0.164 2012 0.038 2013 0.157 2014 1.229 2015 -1.392 2016 -0.627 2017 -0.460 2018 -0.006 2019 0.273 2020 2.000 2021 2.186 2022 3.289 2023 0.650 2024 1.300 2025 1.000 2026 1.000 2027 1.000 2028 1.000 2029 1.000