Year	% of land area
1961	10.020744788504352
1962	10.061222424610403
1963	9.813296903460838
1964	9.70957296093908
1965	9.55525197328476
1966	9.385751872090669
1967	9.193483100586926
1968	9.099878567091682
1969	9.107468123861565
1970	9.00374418133981
1971	9.029042703906091
1972	9.183363691560412
1973	9.178303987047157
1974	9.24408014571949
1975	9.332624974701478
1976	9.347804088241245
1977	9.35792349726776
1978	9.494535519125682
1979	9.53578550881119
1980	9.629380771596137
1981	9.730709653818707
1982	9.839574830547216
1983	9.980194142434701
1984	10.178879748153182
1985	10.231529512480371
1986	10.222710190885415
1987	10.086399792759902
1988	10.175850151951309
1989	10.336870044642959
1990	10.197253832413297
1991	10.310007627244062
1992	10.273026957383397
1993	10.368471554542417
1994	10.604534476578179
1995	10.679322645496407
1996	10.63276342656862
1997	10.495507186601483
1998	10.442465759073787
1999	10.37023843257904
2000	10.323925354840696
2001	10.342633891295964
2002	10.313338894407877
2003	10.28005701530193
2004	10.267958247810517
2005	10.259065167886506
2006	10.278274162942354
2007	10.271524600012857
2008	10.261800109337294
2009	10.254990759689573
2010	10.218082679912865
2011	10.200569812798571
2012	10.199873820700876
2013	10.197092851212567
2014	10.109676514253852
2015	10.083434087829911
2016	10.091091716120856
2017	10.078150567342696
2018	10.077009073484112
2019	10.093599965375532
2020	10.120102364917111
2021	10.009321778007033