Year	% of land area
1961	10.034723115306464
1962	9.948815555955658
1963	9.90766223411096
1964	9.866508912266262
1965	9.825355590421564
1966	9.784202268576866
1967	9.737904781501582
1968	9.696751459656884
1969	9.655598137812186
1970	9.098999459862652
1971	9.099513876385709
1972	9.096941793770416
1973	9.114946372077473
1974	9.098999459862652
1975	9.11134545641606
1976	9.123691452969469
1977	9.14735461303017
1978	9.148897862599346
1979	9.046014557987602
1980	9.084595797217007
1981	9.053216389310425
1982	9.154042027829934
1983	9.428226034620232
1984	9.383471797114124
1985	9.409964248051647
1986	9.436456698989172
1987	9.894287404511433
1988	10.13297667121068
1989	10.625787700300934
1990	11.167468299081767
1991	11.534761696545694
1992	11.537848195684045
1993	11.590318681036035
1994	11.599578178451091
1995	11.605236760204738
1996	11.686000154324958
1997	11.720980477892951
1998	11.74464363795365
1999	11.78939787545976
2000	11.782710460659997
2001	11.909256925332441
2002	11.92623267059338
2003	12.16697960338486
2004	11.94166516628514
2005	11.983847321175956
2006	12.01831322822089
2007	12.09856220581805
2008	11.988991486406544
2009	11.90565600967103
2010	11.79711412330564
2011	11.685485737801898
2012	11.601121428020269
2013	11.569742020113686
2014	11.399984567504308
2015	11.341855500398673
2016	11.188044960004115
2017	10.420535507600503
2018	10.23688880886854
2019	9.97968054733918
2020	10.324854034311583
2021	10.331541449111345