Year	sq. km
1990	578047.2
1991	575343.87
1992	572640.54
1993	569937.21
1994	567233.88
1995	564530.55
1996	561827.22
1997	559123.89
1998	556420.56
1999	553717.23
2000	551013.9
2001	548998.52
2002	546983.14
2003	544967.76
2004	542952.38
2005	540937
2006	538921.62
2007	536906.24
2008	534890.86
2009	532875.48
2010	530860.1
2011	528742.52
2012	526624.94
2013	524507.36
2014	522389.78
2015	520272.2
2016	517506.8
2017	514922.2
2018	512532.4
2019	510337.6
2020	508337.6
2021	506207.73299999995