Year	% of land area
1961	1.4469636550074056
1962	1.4469636550074056
1963	1.4431658501386198
1964	1.4431658501386198
1965	1.4431658501386198
1966	1.4431658501386198
1967	1.4355702404010482
1968	1.4355702404010482
1969	1.4355702404010482
1970	1.4279746306634766
1971	1.4279746306634766
1972	1.4272150696897195
1973	1.411454179484258
1974	1.3956932892787968
1975	1.4564581671793704
1976	1.5172230450799438
1977	1.5236793133568798
1978	1.5301355816338156
1979	1.5950780448900537
1980	1.5191219475143367
1981	1.5779879229805172
1982	1.6634385325281986
1983	1.6957198739128783
1984	1.7317990201663438
1985	1.7811704834605597
1986	1.7659792639854164
1987	1.5950780448900537
1988	1.4203790209259048
1989	1.4374691428354411
1990	1.4431658501386198
1991	1.4469636550074056
1992	1.470081652804679
1993	1.4841232767460406
1994	1.4866833770080892
1995	1.4968975732026888
1996	1.5070886027875887
1997	1.5099248034635981
1998	1.5203869963161292
1999	1.530875773802742
2000	1.533854012380844
2001	1.5255782157912727
2002	1.524438874330637
2003	1.5760890205461244
2004	1.5950780448900537
2005	1.6140670692339827
2006	1.515324142645551
2007	1.6368538984466978
2008	1.7204056055599863
2009	1.7887660931981315
2010	1.8951046295241352
2011	1.7887660931981315
2012	1.9330826782119934
2013	2.0773992632258556
2014	2.2407048725836467
2015	1.8153507272796323
2016	2.0546124340131406
2017	1.8647221905738482
2018	1.969161824465459
2019	2.0736014583570697
2020	2.0014431658501386
2021	2.3394477991720786