Year	% of land area
1961	23.253408730700443
1962	23.24311254769215
1963	23.273654034368427
1964	23.281983530734685
1965	23.312756392310025
1966	23.311830892713772
1967	23.387259109808213
1968	23.42462615600684
1969	23.504913245981598
1970	23.59167883313011
1971	23.83948135002626
1972	24.07478962237303
1973	24.130778325624657
1974	24.143388315976278
1975	24.032906290418488
1976	24.06680286998753
1977	24.05361443971152
1978	24.01601584462641
1979	24.14882565126551
1980	24.010578509337176
1981	23.583643569946112
1982	23.676163878971856
1983	23.758927063353056
1984	23.842062763045554
1985	23.882257396511314
1986	23.887231979861035
1987	23.958634604127283
1988	24.05581251142419
1989	24.007547484133394
1990	24.01788998998142
1991	24.238009518807395
1992	24.447587558451353
1993	24.57891655888403
1994	24.635176736534497
1995	24.64461029345414
1996	24.694877625249596
1997	24.58509119683848
1998	24.695488110745796
1999	24.543634014118563
2000	24.463706724017058
2001	24.54476880913102
2002	24.61092778293232
2003	24.69841178886479
2004	24.799467105057655
2005	22.859218867317697
2006	22.913842226615873
2007	22.962924743746964
2008	22.697720493301556
2009	22.677349099497874
2010	22.726748814990373
2011	22.74987460191083
2012	22.776351732613687
2013	22.81161632655518
2014	22.772889883773896
2015	22.786986559217247
2016	22.851363942669725
2017	22.960554667614144
2018	22.957812563514576
2019	22.867488453466958
2020	22.970386062607044
2021	22.96998708025897