Year	sq. km
1990	54852.9
1991	54874.15
1992	54895.4
1993	54916.65
1994	54937.9
1995	54959.15
1996	54980.4
1997	55001.65
1998	55022.9
1999	55044.15
2000	55065.4
2001	55233.43
2002	55401.46
2003	55569.49
2004	55737.52
2005	55905.55
2006	56073.58
2007	56241.61
2008	56409.64
2009	56577.67
2010	56745.7
2011	56765.94
2012	56786.18
2013	56806.42
2014	56826.66
2015	56846.9
2016	56997.9
2017	57115.9
2018	57215.9
2019	57320.9
2020	57424.9
2021	57529.567