Year % change from 1990 1991 -17.0350441197673 1992 -19.7990357429984 1993 -23.7508766528113 1994 -26.5708274380723 1995 -23.0028810415735 1996 -26.6216549738898 1997 -22.9552302267446 1998 -13.4861580492001 1999 -11.1549335698769 2000 -11.3438262871218 2001 -12.6154921351719 2002 -9.56217453882562 2003 -13.2129600441808 2004 -11.7721948942763 2005 -11.9904111898775 2006 -11.3861011125854 2007 -10.6373724118887 2008 -10.2004510943804 2009 -7.92494141393406 2010 -7.88999748305952 2011 -8.00707185100359 2012 -8.08920228807309