Year	% of land area
1990	1.5354859082655719
1991	1.4867845583010972
1992	1.4380832083366228
1993	1.389381858372148
1994	1.3406805084076736
1995	1.291979158443199
1996	1.2432778084787244
1997	1.1945764585142495
1998	1.145875108549775
1999	1.0971737585853003
2000	1.048472408620826
2001	1.0386674034893817
2002	1.028862398357938
2003	1.0190573932264941
2004	1.0092523880950504
2005	0.9994473829636061
2006	0.9896423778321622
2007	0.9798373727007185
2008	0.9700323675692745
2009	0.9602273624378306
2010	0.9504223573063866
2011	0.9406173521749427
2012	0.9308123470434989
2013	0.921007341912055
2014	0.911202336780611
2015	0.9013973316491671
2016	0.8915923265177231
2017	0.8817873213862795
2018	0.8719823162548354
2019	0.8621773111233916
2020	0.8523723059919476
2021	0.8425673008605037