Year % change from 1990 1991 1.19472004974479 1992 2.32907021319626 1993 3.34147320633522 1994 4.03331210325664 1995 4.6400294605045 1996 5.21052488597638 1997 5.75717420636237 1998 6.26880899269826 1999 6.79010296084106 2000 7.3165283693188 2001 7.80975034033522 2002 8.31293334259005 2003 8.82245518290567 2004 9.34857874195194 2005 9.91665937197208 2006 10.6097056666194 2007 11.4509600321168 2008 12.4057097838456 2009 13.4153961321014 2010 14.5246927927411 2011 15.6699397206685 2012 16.815186648596