Year % change from 1990 1991 1.6675166970249 1992 3.60922890103219 1993 5.72179720704311 1994 7.84796599878568 1995 9.85986642380086 1996 11.7593199757134 1997 13.5414693381906 1998 15.1034608378871 1999 16.3330904675167 2000 17.1463266545234 2001 15.1350333940498 2002 12.6782027929569 2003 9.91997571341834 2004 7.03982999392836 2005 4.16599878567092 2006 5.01979356405586 2007 5.6782027929569 2008 6.33612629022466 2009 7.05950212507591 2010 7.78287795992714 2011 8.86070673952641 2012 9.93853551912569