Year	Square Kilometers
1990	18600
1991	18483
1992	18366
1993	18249
1994	18132
1995	18015
1996	17898
1997	17781
1998	17664
1999	17547
2000	17430
2001	17314
2002	17198
2003	17082
2004	16966
2005	16850
2006	16732
2007	16614
2008	16496
2009	16378
2010	16260
2011	16144
2012	16028
2013	15912
2014	15796
2015	15680