Year	% of land area
1990	94.499110998222
1991	94.47984251968504
1992	94.46057404114809
1993	94.44130556261112
1994	94.42203708407418
1995	94.40276860553722
1996	94.38350012700026
1997	94.36423164846329
1998	94.34496316992634
1999	94.32569469138939
2000	94.30642621285243
2001	94.28386588773178
2002	94.26130556261113
2003	94.23874523749048
2004	94.21618491236983
2005	94.19362458724918
2006	94.17106426212852
2007	94.14850393700786
2008	94.12594361188724
2009	94.10338328676657
2010	94.08082296164592
2011	94.0214376428753
2012	93.96205232410463
2013	93.90266700533401
2014	93.84328168656337
2015	93.78389636779274
2016	93.73716027432056
2017	93.69037338074676
2018	93.64363728727457
2019	93.59685039370078
2020	93.55011430022859
2021	93.50334417068835