Year	sq. km
1961	451770
1962	451850
1963	451820
1964	451900
1965	451870
1966	451950
1967	452020
1968	452100
1969	452270
1970	452050
1971	451820
1972	451600
1973	451370
1974	451150
1975	450930
1976	448700
1977	448480
1978	448250
1979	447930
1980	447650
1981	447280
1982	447050
1983	446780
1984	446500
1985	446280
1986	445450
1987	445230
1988	445010
1989	444780
1990	444560
1991	444830
1992	445110
1993	445100
1994	445100
1995	444900
1996	444470
1997	444500
1998	445130
1999	445670
2000	445230
2001	444150
2002	444380
2003	444990
2004	443100
2005	441830
2006	441370
2007	442450
2008	441950
2009	446300
2010	448500
2011	453160
2012	453030
2013	454880
2014	456740
2015	457890
2016	458240
2017	457720
2018	457920
2019	458770
2020	458920
2021	458970