Year	% of land area
1961	1.34241388636196
1962	1.3465116088478024
1963	1.3506093313336447
1964	1.3547070538194872
1965	1.3588047763053295
1966	1.3620829542940034
1967	1.3670002212770143
1968	1.3670002212770143
1969	1.3670002212770143
1970	1.407977446135438
1971	1.407977446135438
1972	1.407977446135438
1973	1.407977446135438
1974	1.4489546709938617
1975	1.4899318958522854
1976	1.6530212507888116
1977	1.6513821617944746
1978	1.6513821617944746
1979	1.6472844393086323
1980	1.6472844393086323
1981	1.6497430728001379
1982	1.6497430728001379
1983	1.6497430728001379
1984	1.6497430728001379
1985	1.666133962743507
1986	1.6685925962350128
1987	1.6685925962350128
1988	1.6825248526868766
1989	1.6825248526868766
1990	1.6825248526868766
1991	1.6907202976585614
1992	1.772674747375409
1993	2.5078061613355294
1994	2.589760611052377
1995	2.708594563141806
1996	3.7125365721731862
1997	3.7125365721731862
1998	3.7125365721731862
1999	3.7125365721731862
2000	3.7125365721731862
2001	3.7125365721731862
2002	4.015768036125522
2003	4.869733402175071
2004	4.017407125119858
2005	4.591907817634958
2006	4.6525541104254255
2007	4.759914439554495
2008	4.942672862423065
2009	5.126578647587671
2010	5.131168096771814
2011	5.286062006736656
2012	5.440955916701498
2013	5.595849826666339
2014	5.75074373663118
2015	5.9056376465960225
2016	6.061351101058031
2017	6.216245011022874
2018	6.371138920987715
2019	6.526032830952556
2020	6.680926740917398
2021	6.835820650882239