Year	sq. km
1961	146010
1962	146880
1963	147240
1964	147420
1965	147910
1966	148350
1967	148380
1968	149720
1969	149680
1970	149300
1971	149350
1972	149430
1973	149040
1974	149290
1975	149460
1976	149550
1977	149600
1978	149650
1979	149670
1980	149640
1981	149480
1982	149630
1983	149810
1984	149920
1985	150200
1986	150380
1987	150930
1988	151090
1989	147580
1990	147690
1991	147980
1992	147900
1993	147930
1994	147980
1995	147970
1996	147820
1997	147980
1998	147470
1999	147810
2000	148570
2001	147980
2002	148180
2003	148000
2004	141300
2005	141800
2006	140390
2007	136300
2008	136340
2009	136210
2010	141560
2011	139820
2012	137330
2013	139050
2014	138300
2015	138580
2016	135210
2017	133780
2018	134140
2019	138260
2020	130490
2021	130790