Year	% of land area
1961	1.943666934173697
1962	2.153105365147096
1963	2.662021178727319
1964	2.68159486386502
1965	2.7403159192781223
1966	2.838184344966627
1967	2.896905400379729
1968	2.936052770655131
1969	2.936052770655131
1970	2.951711718765292
1971	2.951711718765292
1972	3.13178962203214
1973	3.288379103133747
1974	3.403863845446182
1975	3.484115954510756
1976	3.57024016911664
1977	3.155278044197381
1978	3.264890680968506
1979	3.4586701638317443
1980	3.4899880600520663
1981	3.57415490614418
1982	3.719000176163166
1983	3.728787018732017
1984	3.777721231576269
1985	4.216171778660768
1986	4.3571023116522145
1987	5.010863395251424
1988	5.558926579107048
1989	5.844702382117481
1990	6.085458709311202
1991	6.2948971402846015
1992	6.529781361937012
1993	6.576758206267494
1994	6.772495057644503
1995	6.989762962672982
1996	6.850789798195306
1997	6.655052946818298
1998	6.49846346571669
1999	6.625692419111746
2000	6.694200317093698
2001	6.752921372506802
2002	6.850789798195306
2003	6.956487697938892
2004	6.9584450664526605
2005	7.066100334710016
2006	7.242263500949324
2007	7.438000352326332
2008	7.82947405508035
2009	8.581103564368062
2010	8.808158311965393
2011	8.808158311965393
2012	9.003895163342403
2013	9.19963201471941
2014	9.786842568850437
2015	10.0510873182094
2016	10.129382058760203
2017	10.374053122981463
2018	10.374053122981463
2019	10.569789974358471
2020	10.765526825735481
2021	10.863395251423984