Year	sq. km
1990	586.2
1991	585.94
1992	585.68
1993	585.42
1994	585.16
1995	584.9
1996	584.64
1997	584.38
1998	584.12
1999	583.86
2000	583.6
2001	583.34
2002	583.08
2003	582.82
2004	582.56
2005	582.3
2006	582.04
2007	581.78
2008	581.52
2009	581.26
2010	581
2011	574.8
2012	568.6
2013	562.4
2014	556.2
2015	550
2016	543.8
2017	537.6
2018	531.4
2019	525.2
2020	519
2021	512.8