Year	% of land area
1990	47.59789299993653
1991	47.4069704469971
1992	47.216047894057674
1993	47.02512534111823
1994	46.8342027881788
1995	46.64328023523937
1996	46.45235768229993
1997	46.26143512936049
1998	46.070512576421066
1999	45.879590023481626
2000	45.68866747054219
2001	45.54121765987604
2002	45.39376784920988
2003	45.24631803854371
2004	45.09886822787755
2005	44.9514184172114
2006	44.80396860654523
2007	44.65651879587908
2008	44.50906898521293
2009	44.36161917454676
2010	44.2141693638806
2011	44.09570349685853
2012	43.97723762983647
2013	43.858771762814406
2014	43.74030589579234
2015	43.62184002877028
2016	43.50337416174821
2017	43.38490829472615
2018	43.266442427704085
2019	43.147976560682025
2020	43.02951069365996
2021	42.9110448266379