Year	% of land area
1961	1.871651237259675
1962	2.0196807336344587
1963	2.0024545253374644
1964	2.121246879189826
1965	2.2555270166486596
1966	2.445278705595981
1967	2.508862905640238
1968	2.7871162151959696
1969	2.5560110904286475
1970	2.4073494396209467
1971	2.1942647384246903
1972	2.218996914986397
1973	1.9426473842469052
1974	1.9236426590994886
1975	1.7667885919581374
1976	1.883810837900108
1977	1.9321036668705986
1978	2.165367142652591
1979	2.2480246801088217
1980	2.3151920648764044
1981	2.3724665790193042
1982	2.530882678364552
1983	2.5056298244015465
1984	2.82975150671023
1985	2.7287400908582065
1986	2.691511656665322
1987	2.5513192663655415
1988	2.3607513374900746
1989	2.281478203142288
1990	2.207151504106843
1991	2.2399541803886858
1992	2.112127878369759
1993	2.2273277534071827
1994	2.322611717844916
1995	2.1916613514181953
1996	2.498340340783359
1997	2.721060099189045
1998	2.7791156294338935
1999	2.9931140413678192
2000	3.0554651601733855
2001	3.150098277859495
2002	3.0895695299584762
2003	3.025135701547714
2004	3.350949585410619
2005	3.436731187274644
2006	3.153743019668589
2007	3.010166226260365
2008	3.1232964086276245
2009	3.5330044387748463
2010	3.3312614711739976
2011	4.125704541608633
2012	4.1182198039649585
2013	4.063991252619658
2014	4.160251487184827
2015	4.047056220142405
2016	3.907556142599733
2017	3.997909521816116
2018	4.026770601220486
2019	3.974638651485565
2020	3.9838689967004766
2021	4.064602016115402