Year	% of land area
1961	51.77865612648221
1962	51.87747035573123
1963	51.976284584980235
1964	52.07509881422925
1965	52.17391304347826
1966	52.27272727272727
1967	52.4703557312253
1968	52.4703557312253
1969	52.66798418972331
1970	52.76679841897233
1971	53.063241106719374
1972	53.55731225296443
1973	54.051383399209485
1974	56.7193675889328
1975	56.126482213438734
1976	56.02766798418972
1977	56.7193675889328
1978	57.41106719367589
1979	56.32411067193676
1980	55.63241106719368
1981	57.80632411067194
1982	59.88142292490119
1983	58.00395256916996
1984	56.62055335968379
1985	56.62055335968379
1986	57.31225296442688
1987	57.80632411067194
1988	59.09090909090909
1989	57.11462450592886
1990	57.509881422924906
1991	57.509881422924906
1992	54.1501976284585
1993	54.051383399209485
1994	55.03952569169961
1995	55.03952569169961
1996	55.03952569169961
1997	55.03952569169961
1998	56.02766798418972
1999	56.02766798418972
2000	50
2001	47.82608695652174
2002	48.51778656126482
2003	46.541501976284586
2004	47.233201581027664
2005	47.92490118577075
2006	49.01185770750988
2007	49.01185770750988
2008	55.92885375494071
2009	61.462450592885375
2010	63.63636363636363
2011	63.63636363636363
2012	63.63636363636363
2013	63.63636363636363
2014	63.63636363636363
2015	63.63636363636363
2016	63.63636363636363
2017	62.64822134387352
2018	62.64822134387352
2019	62.64822134387352
2020	62.64822134387352
2021	62.64822134387352