Year	% of land area
1961	23.21416167706264
1962	23.203858318399252
1963	23.23442109016481
1964	23.242756391555414
1965	23.273550699470707
1966	23.272508786796884
1967	23.34775803546208
1968	23.385151123644935
1969	23.465494167604387
1970	23.552088687606798
1971	23.80006390397733
1972	24.035536168261952
1973	24.091447941171023
1974	24.103950951154907
1975	23.993391927686297
1976	24.026964824865246
1977	24.013535665993665
1978	23.975679330209125
1979	24.108581695593383
1980	23.970122436882953
1981	23.542426880545317
1982	23.63478013225406
1983	23.71736945931428
1984	23.800447329912757
1985	23.84078574471632
1986	23.845763794987683
1987	23.917216181673364
1988	24.01446181488136
1989	23.966047381777095
1990	23.97662863281901
1991	24.19713310611814
1992	24.407088743586417
1993	24.538509270750367
1994	24.598301442939967
1995	24.60680348972901
1996	24.657679163502326
1997	24.547983773871486
1998	24.658276529534888
1999	24.508921129160726
2000	24.426551762461333
2001	24.50805286457851
2002	24.57380943560487
2003	24.661734043550794
2004	24.76281329194891
2005	22.821060211560702
2006	22.875811696768956
2007	22.924825591760847
2008	22.65922493974146
2009	22.64339157895468
2010	22.699177558058473
2011	22.720890859105573
2012	22.74583394130576
2013	22.7795258821355
2014	22.740074542551373
2015	22.75302919988248
2016	22.816986337920405
2017	22.926768781184055
2018	22.924136436442154
2019	22.834150764246758
2020	22.939144040850067
2021	22.940689245798644