Year Square Kilometers 1990 20580 1991 20957 1992 21334 1993 21711 1994 22088 1995 22465 1996 22842 1997 23219 1998 23596 1999 23973 2000 24350 2001 24874 2002 25398 2003 25922 2004 26446 2005 26970 2006 27440 2007 27910 2008 28380 2009 28850 2010 29320 2011 29856 2012 30392 2013 30928 2014 31464 2015 32000