Year	% of land area
1961	47.839499372011545
1962	47.99704735253289
1963	48.802415001211905
1964	48.800211532952865
1965	48.8354670250975
1966	49.055813851001474
1967	48.92470748958861
1968	49.27175374038736
1969	50.56959654496177
1970	50.038560694533196
1971	50.15424277813278
1972	50.70400810876318
1973	50.58612255690457
1974	50.115682083599594
1975	49.57473062600533
1976	49.771941035189386
1977	49.957032368948724
1978	49.98567745631624
1979	50.916642795760524
1980	50.545358394112334
1981	50.57841041799793
1982	49.0128462199502
1983	48.481810369521625
1984	49.46565894718287
1985	50.030848555626555
1986	50.415353766828986
1987	51.45539078509574
1988	51.27690985611352
1989	51.9743075600996
1990	51.734129519864275
1991	52.172619703413176
1992	28.44114021595835
1993	28.327178136856947
1994	28.297139073043784
1995	28.0278931166212
1996	27.940587518679873
1997	28.032917658917476
1998	27.968248768054192
1999	27.93627278166648
2000	27.961617190080034
2001	27.923196814877823
2002	27.85551952769981
2003	27.780542309102508
2004	27.73893371892346
2005	27.6880851887539
2006	27.679195760672837
2007	27.587608608166796
2008	27.532500694639634
2009	27.492296078005378
2010	27.766791587995407
2011	27.708697933392273
2012	27.709487347135852
2013	27.692115768463072
2014	27.698783930249437
2015	27.66929621352664
2016	27.659016817398555
2017	27.638457800223055
2018	27.60446655619661
2019	27.507156397279196
2020	27.517804029860795
2021	27.518700956981498