Year Percent change 1980 99.203 1981 100 1982 100 1983 150 1984 16.711 1985 100 1986 143.8 1987 215.4 1988 166.7 1989 130.8 1990 45.4 1991 20.819 1992 42.248 1993 29.969 1994 5.85 1995 6.787 1996 7.516 1997 7.729 1998 5.834 1999 5.759 2000 3.382 2001 1.922 2002 -0.3 2003 8.71 2004 3.666 2005 8.602 2006 7.219 2007 6.09 2008 12.044 2009 13.017 2010 3.716 2011 15.009 2012 12.679 2013 4.905 2014 3.076 2015 5.412 2016 5.455 2017 5.629 2018 2.625 2019 3.6 2020 4.389 2021 4.889 2022 5 2023 5 2024 5