Year	sq. km
1961	149410
1962	149700
1963	150410
1964	148540
1965	142990
1966	136300
1967	136300
1968	134210
1969	134450
1970	134590
1971	134580
1972	141610
1973	144780
1974	145170
1975	141070
1976	142130
1977	140400
1978	140090
1979	139600
1980	140620
1981	141150
1982	141130
1983	139910
1984	139730
1985	139510
1986	139200
1987	139070
1988	137330
1989	134920
1990	134950
1991	135120
1992	136130
1993	136420
1994	137860
1995	137890
1996	137900
1997	138040
1998	137540
1999	137670
2000	137110
2001	137230
2002	137590
2003	138130
2004	139050
2005	138280
2006	138770
2007	138970
2008	138980
2009	139080
2010	139080
2011	139150
2012	139210
2013	139210
2014	139190
2015	139170
2016	139161.26
2017	139200.31
2018	139176.88
2019	139113.34
2020	139133.76
2021	139133.76