Year	Square Kilometers
1990	18010
1991	18126
1992	18242
1993	18358
1994	18474
1995	18590
1996	18706
1997	18822
1998	18938
1999	19054
2000	19170
2001	19302
2002	19434
2003	19566
2004	19698
2005	19830
2006	19956
2007	20082
2008	20208
2009	20334
2010	20460
2011	20506
2012	20552
2013	20598
2014	20644
2015	20690