Year	% of land area
1990	96.22638146167559
1991	95.92844919786097
1992	95.63051693404636
1993	95.33258467023174
1994	95.03465240641712
1995	94.73672014260251
1996	94.43878787878789
1997	94.14085561497325
1998	93.84292335115863
1999	93.54499108734402
2000	93.2470588235294
2001	92.94912655971478
2002	92.65119429590017
2003	92.35326203208555
2004	92.05532976827094
2005	91.75739750445632
2006	91.45946524064172
2007	91.1615329768271
2008	90.86360071301249
2009	90.56566844919786
2010	90.26773618538324
2011	89.96976827094474
2012	89.67180035650624
2013	89.37383244206774
2014	89.07586452762924
2015	88.77789661319073
2016	88.47985739750445
2017	88.18181818181819
2018	87.88377896613191
2019	87.58573975044564
2020	87.28770053475937
2021	86.98966131907308