Year	sq. km
1990	5212.8
1991	5212.52
1992	5212.24
1993	5211.96
1994	5211.68
1995	5211.4
1996	5211.12
1997	5210.84
1998	5210.56
1999	5210.28
2000	5210
2001	5247.45
2002	5284.9
2003	5322.35
2004	5359.8
2005	5397.25
2006	5434.7
2007	5472.15
2008	5509.6
2009	5547.05
2010	5584.5
2011	5622.52
2012	5660.54
2013	5698.56
2014	5736.58
2015	5774.6
2016	5813.4
2017	5852.3
2018	5891.2
2019	5930
2020	5968.9
2021	6007.733