Year	sq. km
1990	16000.3
1991	15859.57
1992	15718.84
1993	15578.11
1994	15437.38
1995	15296.65
1996	15155.92
1997	15015.19
1998	14874.46
1999	14733.73
2000	14593
2001	14525.09
2002	14457.18
2003	14389.27
2004	14321.36
2005	14253.45
2006	14185.54
2007	14117.63
2008	14049.72
2009	13981.81
2010	13913.9
2011	13796.78
2012	13679.66
2013	13562.54
2014	13445.42
2015	13328.3
2016	13216.8
2017	13105.2
2018	12993.7
2019	12882.1
2020	12770.5
2021	12658.9