Year	sq. km
1990	148.269
1991	150.45600000000002
1992	152.642
1993	154.829
1994	157.015
1995	159.202
1996	161.389
1997	163.575
1998	165.762
1999	167.94799999999998
2000	170.135
2001	170.861
2002	171.588
2003	172.315
2004	173.042
2005	173.769
2006	174.49599999999998
2007	175.22299999999998
2008	175.95
2009	176.67700000000002
2010	177.40400000000002
2011	174.86599999999999
2012	172.328
2013	169.79
2014	167.252
2015	164.71400000000003
2016	162.855
2017	161.1
2018	159.3
2019	157.5
2020	155.7
2021	153.9