Year	% of land area
1961	2.299206349206349
1962	2.299206349206349
1963	2.299206349206349
1964	2.299206349206349
1965	2.299206349206349
1966	2.299206349206349
1967	2.299206349206349
1968	2.299206349206349
1969	2.299206349206349
1970	2.299206349206349
1971	2.299206349206349
1972	2.299206349206349
1973	2.3071428571428574
1974	2.3158145442997777
1975	2.3800825921219824
1976	2.4579097839898347
1977	2.4579097839898347
1978	2.4960292249047016
1979	2.4936467598475223
1980	2.491264294790343
1981	2.489675984752224
1982	2.4872935196950445
1983	2.485705209656925
1984	2.4833227445997457
1985	2.485705209656925
1986	2.5254129606099114
1987	2.5254129606099114
1988	2.543678526048285
1989	2.559561626429479
1990	2.599269377382465
1991	2.6381829733163915
1992	2.6540660736975856
1993	2.676302414231258
1994	2.6921855146124525
1995	2.716010165184244
1996	2.7001270648030493
1997	2.8589580686149936
1998	2.8589580686149936
1999	2.8589580686149936
2000	2.8589580686149936
2001	2.9383735705209655
2002	2.9383735705209655
2003	3.0177890724269374
2004	3.0177890724269374
2005	3.0972045743329097
2006	3.0972045743329097
2007	3.0972045743329097
2008	3.0972045743329097
2009	3.176620076238882
2010	3.335451080050826
2011	3.414866581956798
2012	3.6928208386277
2013	3.9707750952986025
2014	4.129606099110546
2015	4.129606099110546
2016	4.209021601016518
2017	4.209021601016518
2018	4.209021601016518
2019	4.209021601016518
2020	4.209021601016518
2021	4.209021601016518