Year	% of land area
1961	1.7618927762396173
1962	1.7895796627233829
1963	1.8348854769695444
1964	1.9154291467404982
1965	1.9733199093883718
1966	2.0362446513969292
1967	2.0362446513969292
1968	2.02617669267556
1969	2.02617669267556
1970	2.02617669267556
1971	2.02617669267556
1972	2.02617669267556
1973	2.023659702995218
1974	2.3156305059149256
1975	2.617669267556003
1976	2.9197080291970803
1977	3.1965768940347346
1978	3.4986156556758115
1979	3.775484520513466
1980	4.077523282154543
1981	4.3820790334759625
1982	4.480241631009313
1983	4.580921218223005
1984	4.681600805436697
1985	4.78228039265039
1986	4.908129876667506
1987	5.008809463881199
1988	5.109489051094891
1989	5.210168638308583
1990	5.3108482255222755
1991	5.411527812735968
1992	5.789076264787314
1993	5.789076264787314
1994	6.166624716838661
1995	6.5441731688900076
1996	6.5441731688900076
1997	6.5441731688900076
1998	7.173420588975585
1999	7.4251195570098165
2000	7.6013088346337785
2001	7.815252957462874
2002	8.079536873898817
2003	8.255726151522778
2004	8.482255222753587
2005	8.708784293984396
2006	8.935313365215203
2007	9.16184243644601
2008	9.456330229046062
2009	9.710546186760634
2010	10.005033979360684
2011	10.375031462371004
2012	10.974075006292475
2013	11.28618172665492
2014	11.736722879436194
2015	12.252705763906368
2016	11.739239869116536
2017	11.711552982632771
2018	11.915429146740498
2019	11.915429146740498
2020	11.915429146740498
2021	11.915429146740498