Year Measure 1990 3358.61346 1991 3200.13243 1992 2990.01849 1993 2569.30767 1994 2522.2577 1995 2405.15051 1996 2327.87535 1997 2047.76248 1998 2088.11777 1999 2189.41122 2000 2161.60825 2001 2140.30859 2002 2133.63302 2003 2127.14941 2004 2143.95068 2005 2129.21291 2006 2113.97465 2007 2047.14931 2008 1920.4545 2009 1883.4927 2010 1864.91625 2011 1783.78851 2012 1734.57066 2013 1668.29526 2014 1479.77727