Year Percent change (Units) 1980 1.300 1981 3.578 1982 3.555 1983 3.859 1984 5.595 1985 0.228 1986 2.288 1987 4.561 1988 10.295 1989 8.776 1990 4.579 1991 2.789 1992 2.379 1993 0.887 1994 8.998 1995 5.524 1996 3.717 1997 9.994 1998 4.759 1999 4.486 2000 11.807 2001 2.134 2002 7.974 2003 -0.302 2004 6.892 2005 4.367 2006 4.408 2007 4.706 2008 -2.243 2009 -10.694 2010 8.248 2011 4.349 2012 -1.624 2013 2.709 2014 1.813 2015 1.291 2016 3.116 2017 0.856 2018 0.737 2019 0.048 2020 -6.399 2021 14.718 2022 7.196 2023 -3.324 2024 -0.556 2025 2.920 2026 3.411 2027 3.318 2028 3.298 2029 3.193