Year	sq. km
1961	45580
1962	46137
1963	46169
1964	46596
1965	47078
1966	47537
1967	47826
1968	48029
1969	48160
1970	47943
1971	48240
1972	48274
1973	48420
1974	48488
1975	48355
1976	48520
1977	48808
1978	48853
1979	48962
1980	49315
1981	49091
1982	48952
1983	48765
1984	48934
1985	48836
1986	48449
1987	48170
1988	48005
1989	46767
1990	45374
1991	44448
1992	44162
1993	44073
1994	43936
1995	43887
1996	43418
1997	43556.4
1998	43694.8
1999	43833.2
2000	43961.6
2001	44100
2002	43730
2003	43700
2004	43050
2005	43020
2006	42600
2007	42760
2008	46290
2009	45939.2
2010	45680
2011	45550
2012	45330
2013	44770
2014	44660
2015	44300
2016	44610
2017	44890
2018	45160
2019	45240
2020	45120
2021	43370