Year	% of land area
1961	7.605380590067097
1962	7.6214324697422065
1963	7.634273973482294
1964	7.6567466050274495
1965	7.672798484702559
1966	7.688850364377668
1967	7.704902244052779
1968	7.720954123727888
1969	7.737006003402999
1970	7.7530578830781085
1971	7.769109762753218
1972	7.785161642428329
1973	7.801213522103438
1974	7.817265401778549
1975	7.8493691611287675
1976	7.865421040803879
1977	7.881472920478988
1978	7.897524800154097
1979	7.913576679829208
1980	7.937654499341873
1981	7.937654499341873
1982	7.945680439179428
1983	7.945680439179428
1984	7.948890815114449
1985	7.950496003081961
1986	7.952101191049472
1987	7.953706379016983
1988	7.955311566984494
1989	7.955311566984494
1990	7.955311566984494
1991	7.958521942919516
1992	7.961732318854538
1993	7.961732318854538
1994	7.961732318854538
1995	7.945680439179428
1996	7.945680439179428
1997	7.945680439179428
1998	7.945680439179428
1999	7.945680439179428
2000	7.948890815114449
2001	7.948890815114449
2002	7.948890815114449
2003	7.937654499341873
2004	7.937654499341873
2005	7.937654499341873
2006	7.929628559504318
2007	7.929628559504318
2008	7.929628559504318
2009	7.923207807634274
2010	7.876657356576455
2011	7.8252913416161025
2012	7.833317281453659
2013	7.842948409258724
2014	7.876657356576455
2015	7.876657356576455
2016	7.876657356576455
2017	7.876657356576455
2018	7.879867732511476
2019	7.879867732511476
2020	7.879867732511476
2021	7.881472920478988