Year	% of land area
1961	12.629370629370628
1962	12.629370629370628
1963	12.6993006993007
1964	12.629370629370628
1965	12.629370629370628
1966	12.629370629370628
1967	12.72027972027972
1968	12.72027972027972
1969	12.72027972027972
1970	13.657342657342658
1971	13.657342657342658
1972	14.37062937062937
1973	15.13986013986014
1974	15.244755244755245
1975	15.349650349650348
1976	15.454545454545453
1977	15.55944055944056
1978	15.664335664335665
1979	15.769230769230768
1980	15.874125874125875
1981	16
1982	16.025174825174826
1983	16.05034965034965
1984	16.075524475524475
1985	16.1006993006993
1986	16.125874125874127
1987	16.151048951048953
1988	16.17622377622378
1989	16.2013986013986
1990	16.226573426573427
1991	16.251748251748253
1992	16.274825174825175
1993	16.2979020979021
1994	16.32097902097902
1995	16.344055944055942
1996	16.367132867132867
1997	16.390209790209788
1998	16.413286713286713
1999	16.436363636363634
2000	16.42134635507499
2001	16.428322288106035
2002	16.288803627485176
2003	16.149284966864318
2004	16.044645971398673
2005	15.905127310777816
2006	15.76560865015696
2007	15.626089989536101
2008	15.486571328915241
2009	15.347052668294383
2010	15.207534007673527
2011	15.086850366236485
2012	14.775026159748867
2013	14.747122427624696
2014	14.745029647715382
2015	14.745029647715382
2016	14.745029647715382
2017	14.745029647715382
2018	14.745029647715382
2019	14.745029647715382
2020	14.745029647715382
2021	14.745029647715382