Year	% of land area
1961	6.976669636481411
1962	7.00463600609291
1963	7.041556035540503
1964	7.065985156821694
1965	7.10257356923832
1966	7.129213470725954
1967	7.171881528710297
1968	7.291484737878845
1969	7.300991092766548
1970	7.214217969663674
1971	7.2480429068222465
1972	7.272803645134404
1973	7.269045318783452
1974	7.205582909029005
1975	7.26913544216198
1976	7.336570201795754
1977	7.352599775807062
1978	7.399914656336988
1979	7.476967160377546
1980	7.534784175604536
1981	7.515548686790968
1982	7.579335336477341
1983	7.622891558273582
1984	7.674960036613758
1985	7.7211694292808355
1986	7.748806625852055
1987	7.751459796722892
1988	7.8464212041416
1989	7.883455047547033
1990	8.073488411170734
1991	8.300223971841014
1992	8.55503892422765
1993	8.697978504893994
1994	8.833621865665537
1995	9.197659018901632
1996	9.421409762342218
1997	9.514491840394085
1998	9.6136824574553
1999	9.822758568083682
2000	9.842906814006088
2001	9.950114429048684
2002	10.042955123825696
2003	10.234850847577544
2004	10.178284868745425
2005	10.311224924771551
2006	10.320302804180512
2007	10.41759640406908
2008	10.575544806528569
2009	10.759210184196387
2010	10.766314767770165
2011	10.846076435641812
2012	10.992473595422396
2013	11.262904282438884
2014	11.325320856797314
2015	11.40483378989982
2016	11.539842213717336
2017	11.604873255816525
2018	11.674326260421987
2019	11.764894072152982
2020	11.805502968071385
2021	11.845742757418298