Year	% of land area
1961	1.4389475817714483
1962	1.4449978168735007
1963	1.4460061893905094
1964	1.453568983268075
1965	1.4626443359211534
1966	1.4727280610912405
1967	1.4893662076218845
1968	1.4979373740164588
1969	1.5009624915674848
1970	1.515079706805607
1971	1.5170964518396244
1972	1.5337345983702684
1973	1.5453308823158687
1974	1.5145755205471025
1975	1.4830134607647296
1976	1.4878536488463714
1977	1.4601234046286315
1978	1.4923913251729106
1979	1.4989457465334675
1980	1.4919879761661072
1981	1.485030205798747
1982	1.5034834228600067
1983	1.505500167894024
1984	1.5271801770097115
1985	1.5220374771729672
1986	1.4990465837851683
1987	1.5253651064790958
1988	1.5404906942342267
1989	1.5243567339620872
1990	1.54664176658798
1991	1.4985423975266638
1992	1.983706222319632
1993	2.039042276547978
1994	2.047371786648148
1995	2.024933614215003
1996	2.0303326446680114
1997	2.018494403582975
1998	1.982335759264662
1999	1.9853077026332904
2000	2.0493580354661813
2001	1.9039804723507725
2002	1.8790211012932412
2003	1.825913335588697
2004	1.8445849680103985
2005	1.8929590507369518
2006	1.9275532605366286
2007	1.9345857167620037
2008	2.002931996781402
2009	2.0426227829051884
2010	2.0510513615994483
2011	2.068603398283918
2012	2.0292612062491537
2013	1.9338059953094737
2014	2.0149327930790752
2015	1.9380693360004686
2016	2.005391128780201
2017	2.0271404740240047
2018	2.041652432703298
2019	2.039893370901115
2020	2.043276333684956
2021	2.0440137472200863