Year	% of land area
1990	14.955271249453874
1991	14.925265231763513
1992	14.89525921407315
1993	14.865253196382792
1994	14.835247178692429
1995	14.805241161002069
1996	14.775235143311708
1997	14.745229125621348
1998	14.715223107930985
1999	14.685217090240624
2000	14.655211072550264
2001	14.625205054859903
2002	14.595199037169543
2003	14.56519301947918
2004	14.535187001788819
2005	14.505180984098459
2006	14.475174966408098
2007	14.445168948717738
2008	14.415162931027375
2009	14.385156913337017
2010	14.355150895646654
2011	14.325144877956292
2012	14.295138860265933
2013	14.26513284257557
2014	14.23512682488521
2015	14.205120807194849
2016	14.175114789504489
2017	14.145108771814128
2018	14.115102754123765
2019	14.085096736433405
2020	14.055090718743044
2021	14.025084701052684