Year % change from 1990 1991 -24.2166431097287 1992 -40.3919160817236 1993 -36.7588372360365 1994 -31.8646599005304 1995 -31.0374748106045 1996 -27.9128080124984 1997 -28.5307754326739 1998 -31.3508973178149 1999 -33.3485859403739 2000 -29.1998900952849 2001 -28.2288528381702 2002 -24.5812394195505 2003 -23.5738352420206 2004 -23.9878081561615 2005 -24.4285045214786 2006 -24.5675910319141 2007 -24.8835417886899 2008 -25.1238462347109 2009 -26.4388438089106 2010 -25.2725310128623 2011 -24.5252563229909 2012 -23.7779816331196