Year	% of land area
1992	12.984776086231802
1993	12.979219913323703
1994	12.846982998110901
1995	12.859391784272326
1996	12.226395525428751
1997	12.057561951327925
1998	11.910508575026855
1999	11.874023039596992
2000	11.171352372485831
2001	10.875171315331333
2002	10.499648109049154
2003	10.498796162536578
2004	10.548875801014928
2005	10.579805163536689
2006	10.59969626254769
2007	10.609030633033301
2008	10.564062673630403
2009	10.600511167907545
2010	10.624810164092306
2011	10.808830610808608
2012	10.865096121791309
2013	10.88813571878357
2014	10.916101789087676
2015	10.964588657999037
2016	10.979812571767233
2017	10.985294662369894
2018	11.019002111345705
2019	10.882060969737378
2020	10.946845945845835
2021	10.989998888765419