Year	Square Kilometers
1990	627950
1991	625246
1992	622542
1993	619838
1994	617134
1995	614430
1996	611726
1997	609022
1998	606318
1999	603614
2000	600910
2001	598196
2002	595482
2003	592768
2004	590054
2005	587340
2006	582290
2007	577240
2008	572190
2009	567140
2010	562090
2011	559200
2012	556310
2013	553420
2014	550530
2015	547640