Year	% of land area
1990	92.21725462801258
1991	92.19334031901269
1992	92.1694260100128
1993	92.14551170101292
1994	92.12159739201304
1995	92.09768308301317
1996	92.07376877401327
1997	92.04985446501338
1998	92.02594015601349
1999	92.00202584701363
2000	91.97811153801374
2001	91.9584778980867
2002	91.93884425815966
2003	91.91921061823263
2004	91.89957697830559
2005	91.87994333837854
2006	91.8603096984515
2007	91.84067605852448
2008	91.82104241859743
2009	91.80140877867039
2010	91.78177513874336
2011	91.7356618931191
2012	91.68954864749486
2013	91.6434354018706
2014	91.59732215624636
2015	91.55120891062212
2016	91.50510342686383
2017	91.45899794310553
2018	91.41289245934723
2019	91.36678697558894
2020	91.32068149183064
2021	91.27457600807234