Year	% of land area
1961	5.8703996387446375
1962	5.701061187627004
1963	6.8864303454504405
1964	6.773538044705352
1965	6.773538044705352
1966	6.773538044705352
1967	6.773538044705352
1968	6.773538044705352
1969	6.773538044705352
1970	7.902461052156243
1971	7.902461052156243
1972	7.902461052156243
1973	7.902461052156243
1974	7.902461052156243
1975	7.902461052156243
1976	7.902461052156243
1977	7.902461052156243
1978	9.031384059607134
1979	9.031384059607134
1980	9.031384059607134
1981	9.031384059607134
1982	9.031384059607134
1983	9.031384059607134
1984	9.031384059607134
1985	10.160307067058026
1986	10.160307067058026
1987	10.160307067058026
1988	10.160307067058026
1989	10.160307067058026
1990	10.160307067058026
1991	10.16369383608038
1992	9.934522465567849
1993	10.047414766312937
1994	10.047414766312937
1995	10.047414766312937
1996	10.160307067058026
1997	10.056446150372544
1998	9.84985324000903
1999	9.821630164822759
2000	9.70873786407767
2001	9.629713253556108
2002	9.70873786407767
2003	9.641002483630617
2004	10.269925491081509
2005	10.8988484985324
2006	11.527771505983292
2007	12.156694513434184
2008	12.785843305486566
2009	12.990629939038156
2010	13.19541657258975
2011	13.400203206141342
2012	13.604989839692932
2013	13.809776473244526
2014	14.014563106796116
2015	14.21934974034771
2016	14.424136373899298
2017	14.628923007450892
2018	14.833709641002486
2019	15.038496274554076
2020	15.243282908105668
2021	15.243282908105668