Year	% of land area
1990	26.81046511627907
1991	26.881046511627904
1992	26.951627906976743
1993	27.022209302325578
1994	27.092790697674417
1995	27.16337209302326
1996	27.23395348837209
1997	27.304534883720933
1998	27.375116279069772
1999	27.445697674418607
2000	27.516279069767442
2001	27.58691860465116
2002	27.65755813953489
2003	27.728197674418603
2004	27.798837209302324
2005	27.869476744186052
2006	27.940116279069766
2007	28.01075581395349
2008	28.08139534883721
2009	28.152034883720926
2010	28.222674418604655
2011	28.29325581395349
2012	28.36383720930232
2013	28.434418604651164
2014	28.504999999999995
2015	28.575581395348838
2016	28.646511627906975
2017	28.716860465116277
2018	28.78720930232558
2019	28.857558139534884
2020	28.92790697674419
2021	28.998255813953488