Year	% of land area
1961	32.26987247118995
1962	32.27966417712543
1963	32.2886399075663
1964	32.30006356449103
1965	32.30336826524426
1966	32.319687775136735
1967	32.33396734629265
1968	32.323359664862544
1969	32.308264118212
1970	32.25420574169316
1971	32.23645827468509
1972	32.25155382133564
1973	32.26958687976683
1974	32.23356156167918
1975	32.13315633115943
1976	32.150634221526325
1977	32.12960022748098
1978	32.12978042537637
1979	32.09352939832588
1980	32.05066300736321
1981	32.05227113986187
1982	32.04718840979412
1983	32.02762236934867
1984	32.045804665979084
1985	32.06251823668029
1986	32.073968832003864
1987	32.104904565452955
1988	32.113801250375346
1989	32.096954392796064
1990	32.11711130984242
1991	32.10924640888844
1992	32.10420220982871
1993	32.172329923915385
1994	32.214572952384934
1995	32.22125062953916
1996	32.24689993412197
1997	32.246061365849776
1998	32.22910494704234
1999	32.24197254666629
2000	32.28338595403169
2001	32.21387462112092
2002	32.151441498980475
2003	32.188435618047215
2004	32.20446440206768
2005	32.25720937079441
2006	32.27992565591136
2007	32.271049205956785
2008	32.31850650545575
2009	32.37104140097321
2010	32.35253657365737
2011	32.38530364576541
2012	32.37051355649121
2013	32.238984846879305
2014	32.316285211338005
2015	32.262595208608175
2016	32.31982536236549
2017	32.345799439349236
2018	32.3509145275834
2019	32.345950295297634
2020	32.34529410329718
2021	32.343723990597226