Year	% of land area
1961	0.8245280596799283
1962	0.8357452446498359
1963	0.8631169083601896
1964	0.8712591121221303
1965	0.8839055137098254
1966	0.8913980735545899
1967	0.8989772525883113
1968	0.9081588866177338
1969	0.9204155018551232
1970	0.9430664197673304
1971	0.9562325364887665
1972	0.9750289004923954
1973	0.9897472153181797
1974	1.002471596219447
1975	1.0136436758391372
1976	1.042652316585528
1977	1.0600193887552842
1978	1.0899611545367915
1979	1.1182063402368752
1980	1.1455338279494618
1981	1.1619268575657402
1982	1.1772073948103832
1983	1.1220257752717737
1984	1.1430613497109985
1985	1.1885606683871612
1986	1.2446041448198417
1987	1.3084756137077747
1988	1.3441284834701854
1989	1.3767683663424441
1990	1.3817449428350577
1991	1.386634250659313
1992	0.8567231399785707
1993	0.8811257095978129
1994	0.9049734204800284
1995	0.9113634460695113
1996	0.9191986547637225
1997	0.9342842479064994
1998	0.9431053221678796
1999	0.9572968113919852
2000	0.9701912882219413
2001	0.9833528153130919
2002	0.9928387560677172
2003	1.0127359217727558
2004	1.0356755536887108
2005	1.0669580209995864
2006	1.0830073118605448
2007	1.0975933900127015
2008	1.107784109644087
2009	1.1182336991301254
2010	1.1449440991500823
2011	1.1624458278067364
2012	1.1794289061157324
2013	1.1906893998991324
2014	1.1912743386306708
2015	1.216432782376374
2016	1.2278288401622435
2017	1.2371149597164854
2018	1.2590403979072067
2019	1.2899870250012742
2020	1.2919945360304692
2021	1.2969206676824707