Year	Square Kilometers
1990	644170
1991	641551.4
1992	638932.9
1993	636314.3
1994	633695.8
1995	631077.2
1996	628458.6
1997	625840.1
1998	623221.5
1999	620603
2000	617984.4
2001	614790.2
2002	611596.1
2003	608401.9
2004	605207.8
2005	602013.6
2006	598881.5
2007	595749.4
2008	592617.4
2009	589485.3
2010	586353.2
2011	586086
2012	585818.9
2013	585551.7
2014	585284.6
2015	585017.4