Year	sq. km
1990	22333.3
1991	22248.85
1992	22164.4
1993	22079.95
1994	21995.5
1995	21911.05
1996	21826.6
1997	21742.15
1998	21657.7
1999	21573.25
2000	21488.8
2001	21404.35
2002	21319.9
2003	21235.45
2004	21151
2005	21066.55
2006	20982.1
2007	20897.65
2008	20813.2
2009	20728.75
2010	20644.3
2011	20559.86
2012	20475.42
2013	20390.98
2014	20306.54
2015	20222.1
2016	20137.7
2017	20053.3
2018	19968.9
2019	19884.5
2020	19800.1
2021	19715.7