Year % change from 1990 1991 1.49773541758416 1992 3.09890225326961 1993 4.43058176132394 1994 6.06205077028126 1995 7.38807387265816 1996 14.0234417612431 1997 16.2944886407253 1998 14.4201982166161 1999 19.6749990909348 2000 24.0078058398348 2001 26.3689511811787 2002 30.8997321287883 2003 32.9574517084365 2004 34.3339784329332 2005 36.7609804975213 2006 38.8465780765797 2007 39.9297797638047 2008 41.3899404865317 2009 43.3110982719681 2010 45.2811435636164 2011 46.7339549992525 2012 48.1867664348887