Year	% of land area
1961	9.488119917078617
1962	9.201084356561951
1963	12.629564662733216
1964	12.59767182267581
1965	12.64551108276192
1966	12.629564662733216
1967	12.629564662733216
1968	12.725243182905437
1969	12.820921703077659
1970	12.91660022324988
1971	13.012278743422101
1972	13.107957263594322
1973	13.203635783766545
1974	13.299314303938766
1975	13.554457024398022
1976	14.3517780258332
1977	15.14909902726838
1978	15.946420028703557
1979	14.3517780258332
1980	14.3517780258332
1981	14.3517780258332
1982	13.666081964598947
1983	13.857439004943389
1984	13.9052782650295
1985	13.969063945144313
1986	14.144474565460055
1987	14.272045925689683
1988	14.319885185775794
1989	14.367724445861905
1990	14.3517780258332
1991	14.39961728591931
1992	14.431510125976718
1993	14.03284962525913
1994	14.080688885345241
1995	14.128528145431352
1996	14.144474565460055
1997	14.16042098548876
1998	14.176367405517462
1999	14.431510125976718
2000	14.590974326263753
2001	14.606920746292456
2002	14.925849146866529
2003	15.14909902726838
2004	14.3517780258332
2005	17.54106203157391
2006	16.743741030138732
2007	15.946420028703557
2008	19.135704034444267
2009	19.135704034444267
2010	19.135704034444267
2011	20.73034603731462
2012	20.73034603731462
2013	20.73034603731462
2014	20.73034603731462
2015	21.00399075824407
2016	21.165559917922867
2017	21.330360460795244
2018	22.171214276477436
2019	22.170606165380548
2020	22.17911412867766
2021	22.17911412867766