Year Percent change 1980 316.595 1981 116.808 1982 120.365 1983 145.637 1984 373.821 1985 304.584 1986 48.155 1987 19.853 1988 16.231 1989 20.249 1990 17.173 1991 19.006 1992 11.948 1993 10.944 1994 12.342 1995 10.043 1996 11.277 1997 9.001 1998 5.435 1999 5.194 2000 1.125 2001 1.116 2002 5.687 2003 0.65 2004 -0.4 2005 1.351 2006 2.095 2007 0.528 2008 4.589 2009 3.307 2010 2.706 2011 3.429 2012 1.718 2013 1.511 2014 0.485 2015 -0.632 2016 -0.544 2017 0.244 2018 0.815 2019 0.885 2020 1.672 2021 1.998 2022 1.998 2023 1.998 2024 1.998