Year	% of land area
1990	78.36812144212524
1991	78.06451612903226
1992	77.76091081593928
1993	77.4573055028463
1994	77.15370018975332
1995	76.85009487666035
1996	76.54648956356736
1997	76.24288425047439
1998	75.9392789373814
1999	75.63567362428843
2000	75.33206831119544
2001	75.00948766603416
2002	74.68690702087287
2003	74.36432637571157
2004	74.04174573055028
2005	73.719165085389
2006	73.39658444022771
2007	73.07400379506642
2008	72.75142314990512
2009	72.42884250474383
2010	72.10626185958255
2011	72.10626185958255
2012	72.10626185958255
2013	72.10626185958255
2014	72.10626185958255
2015	72.10626185958255
2016	72.10626185958255
2017	72.10626185958255
2018	72.10626185958255
2019	72.10626185958255
2020	72.10626185958255
2021	72.10626185958255