Year % change from 1990 1991 -10.6904171662432 1992 31.7232201332391 1993 7.54704870184617 1994 -5.82317644066708 1995 7.80975378443818 1996 -18.9707651044476 1997 -19.667219112193 1998 -70.2201118119934 1999 -99.4932034294477 2000 -99.0590725436437 2001 -98.8075374810533 2002 -97.7548166635458 2003 -98.2206223350093 2004 -97.866610024697 2005 -97.5964427352482 2006 -97.2610626517944 2007 -96.9536309086285 2008 -96.6461991654626 2009 -96.3201351954385 2010 -96.022019565701 2011 -96.0220195657012 2012 -96.0220195657012