Year % change from 1990 1991 2.59827140417221 1992 5.30581690995211 1993 8.04068094113395 1994 10.7284366489849 1995 13.3348821001278 1996 15.8350649406521 1997 18.3462182126371 1998 20.598598366051 1999 23.0172558433681 2000 25.4458082196495 2001 27.8898482638755 2002 30.3556140645233 2003 32.6617708427443 2004 34.9918044423794 2005 37.296670581605 2006 39.6277797137363 2007 42.1417293702112 2008 44.8707855259139 2009 47.7177200431934 2010 50.7606165812694 2011 52.2682227470821 2012 53.7758289128948