Year	sq. km
1990	649581.4
1991	647358.76
1992	645136.12
1993	642913.48
1994	640690.84
1995	638468.2
1996	636245.56
1997	634022.92
1998	631800.28
1999	629577.64
2000	627355
2001	625427.29
2002	623499.58
2003	621571.87
2004	619644.16
2005	617716.45
2006	615788.74
2007	613861.03
2008	611933.32
2009	610005.61
2010	608077.9
2011	606731.64
2012	605385.38
2013	604039.12
2014	602692.86
2015	601346.6
2016	599594.9
2017	597397.7
2018	595404.8
2019	593412
2020	591419.1
2021	589426.267