Year Percent change (Units) 1980 0.700 1981 -5.744 1982 -3.149 1983 3.733 1984 2.000 1985 -6.951 1986 7.146 1987 2.529 1988 -1.957 1989 -7.007 1990 -1.338 1991 10.498 1992 10.299 1993 6.251 1994 5.830 1995 -2.845 1996 5.527 1997 8.111 1998 3.850 1999 -3.385 2000 -0.789 2001 -4.409 2002 -10.894 2003 8.955 2004 8.911 2005 8.852 2006 8.047 2007 9.008 2008 4.057 2009 -5.919 2010 10.125 2011 6.004 2012 -1.026 2013 2.405 2014 -2.513 2015 2.731 2016 -2.080 2017 2.818 2018 -2.617 2019 -2.001 2020 -9.900 2021 10.718 2022 4.956 2023 -1.569 2024 -2.764 2025 5.003 2026 4.495 2027 3.900 2028 3.100 2029 2.301