Year	% of land area
1961	1.1433824922164713
1962	1.1661122203156065
1963	1.2051175561894312
1964	1.2426496689457194
1965	1.2626504266033227
1966	1.279978336604824
1967	1.3064261992386945
1968	1.3192642864057986
1969	1.329366387783192
1970	1.347255525638993
1971	1.3525170367730521
1972	1.3783335180708354
1973	1.403170803743117
1974	1.4338319633460288
1975	1.4712260170039082
1976	1.5031460527543483
1977	1.520754687860635
1978	1.54250240452577
1979	1.579894446404857
1980	1.6102710958113196
1981	1.6331412752720744
1982	1.654748684087757
1983	1.5151050358156524
1984	1.5370645472656106
1985	1.664581595022573
1986	1.8001989812970993
1987	1.9468910491386076
1988	2.056688606388399
1989	2.1070436013760987
1990	2.2130631101141827
1991	2.2242655925006165
1992	2.2448311143030053
1993	2.3545560829348293
1994	2.4743423376176685
1995	2.6055836547562214
1996	2.6358957571036155
1997	2.666838996760987
1998	2.6811399623286065
1999	2.757517243037088
2000	2.792835807449633
2001	2.870518473776992
2002	2.9335653176332532
2003	3.0202659984046525
2004	3.083769194243178
2005	3.148110066293174
2006	3.249393551523623
2007	3.3852433150334065
2008	3.4671597156002583
2009	3.5773213774131962
2010	3.6654292411887948
2011	3.7894191228087815
2012	3.861563492154069
2013	3.93652300825175
2014	3.9813771454461135
2015	4.0765462494098506
2016	4.1576143516448
2017	4.375568098757216
2018	4.459740539519825
2019	4.553935900117018
2020	4.589338550990155
2021	4.616932436117128