Year	% of land area
1961	0.39207498144023756
1962	0.39683092056421676
1963	0.4064587973273942
1964	0.4174786562731997
1965	0.4228145879732739
1966	0.42525055679287305
1967	0.4333704528582034
1968	0.43638641425389757
1969	0.4577301410541945
1970	0.48058184855233854
1971	0.49044172234595396
1972	0.5074935040831478
1973	0.5206037518733847
1974	0.5257077102250846
1975	0.5297676770957549
1976	0.5425275729750045
1977	0.5565634584421791
1978	0.5569114556025223
1979	0.5617834158473267
1980	0.5618994149007744
1981	0.5743113136196809
1982	0.5925231650109735
1983	0.6261628905108134
1984	0.6524946756434468
1985	0.6672265554313077
1986	0.6818424361657209
1987	0.7007502818776998
1988	0.7336940130568534
1989	0.7507458739136689
1990	0.7698857177325433
1991	0.7762085345340204
1992	0.7854635733242017
1993	0.7771340384130385
1994	0.7882400849612561
1995	0.8013243960508749
1996	0.8185619057975877
1997	0.8200658496009922
1998	0.8281640085424008
1999	0.8251561209355919
2000	0.8340640957711414
2001	0.8391543671057411
2002	0.8701587470528486
2003	0.8836095444685467
2004	0.9014279714891603
2005	0.9729364522029262
2006	0.9909310614903879
2007	1.0119507623961683
2008	1.0048705430481963
2009	1.0027495894710166
2010	1.0550520293289882
2011	1.080210339209006
2012	1.086565879129018
2013	1.1314802024930195
2014	1.1510703281808958
2015	1.147690991262791
2016	1.1713685624578105
2017	1.1731278060051913
2018	1.1689636239466932
2019	1.1663806742056573
2020	1.1344005907229582
2021	1.1785003048113876