Year	% of land area
1990	90.92211504108609
1991	90.8959985709182
1992	90.86988210075026
1993	90.84376563058234
1994	90.81764916041443
1995	90.79153269024651
1996	90.7654162200786
1997	90.73929974991069
1998	90.71318327974276
1999	90.68706680957486
2000	90.66095033940694
2001	90.63479814219365
2002	90.60864594498035
2003	90.58249374776707
2004	90.55634155055378
2005	90.53018935334049
2006	90.5040371561272
2007	90.47788495891389
2008	90.4517327617006
2009	90.42558056448732
2010	90.39942836727403
2011	90.37327617006073
2012	90.34712397284744
2013	90.32097177563415
2014	90.29481957842087
2015	90.26866738120758
2016	90.24258663808503
2017	90.21650589496248
2018	90.19042515183993
2019	90.1643444087174
2020	90.13826366559485
2021	90.11218292247231