Year	% of land area
1961	2.112621955903818
1962	2.1510332641929786
1963	2.112621955903818
1964	2.1510332641929786
1965	1.997388031036337
1966	1.9359299377736807
1967	1.9359299377736807
1968	1.8437427978796959
1969	2.0357993393254974
1970	1.997388031036337
1971	1.982023507720673
1972	1.982023507720673
1973	1.982023507720673
1974	1.982023507720673
1975	1.997388031036337
1976	1.997388031036337
1977	1.997388031036337
1978	2.0127525543520015
1979	2.0357993393254974
1980	2.0434816009833296
1981	2.089575170930322
1982	2.1049396942459864
1983	2.112621955903818
1984	2.112621955903818
1985	2.112621955903818
1986	2.1510332641929786
1987	2.1510332641929786
1988	2.227855880771299
1989	2.227855880771299
1990	2.5351463470845816
1991	2.573557655373742
1992	2.6119689636629024
1993	2.6119689636629024
1994	2.688791580241223
1995	2.8424368133978644
1996	2.8424368133978644
1997	2.8808481216870248
1998	2.919259429976185
1999	3.4570177460244293
2000	3.4570177460244293
2001	3.8411308289160324
2002	3.8411308289160324
2003	3.8411308289160324
2004	4.455711761542598
2005	6.145809326265653
2006	6.145809326265653
2007	6.529922409157256
2008	6.529922409157256
2009	6.529922409157256
2010	6.529922409157256
2011	6.529922409157256
2012	6.5529691941307515
2013	7.682261657832065
2014	8.074057002381501
2015	8.465852346930937
2016	8.857647691480372
2017	9.249443036029808
2018	9.641238380579242
2019	10.025351463470846
2020	10.202043481600983
2021	10.432511331335945