Year	% of land area
1990	38.845511561425404
1991	38.840258588670686
1992	38.83500561591596
1993	38.82975264316124
1994	38.82449967040652
1995	38.8192466976518
1996	38.81399372489708
1997	38.808740752142356
1998	38.80348777938764
1999	38.79823480663292
2000	38.7929818338782
2001	38.78763070807387
2002	38.782279582269545
2003	38.77692845646522
2004	38.7715773306609
2005	38.766226204856565
2006	38.76087507905224
2007	38.755523953247916
2008	38.7501728274436
2009	38.74482170163927
2010	38.73947057583494
2011	38.73486407475693
2012	38.73025757367892
2013	38.72565107260091
2014	38.7210445715229
2015	38.716438070444894
2016	38.71201337558376
2017	38.7078876013737
2018	38.7037629425392
2019	38.69963716832913
2020	38.695512509494634
2021	39.47012792563178