Year	% of land area
1990	35.59405263757548
1991	35.775652272986214
1992	35.95725190839694
1993	36.13885154380768
1994	36.320451179218416
1995	36.50205081462914
1996	36.68365045003988
1997	36.865250085450604
1998	37.04684972086134
1999	37.22844935627207
2000	37.41004899168281
2001	37.40916790095325
2002	37.40828681022369
2003	37.407405719494136
2004	37.40652462876457
2005	37.405643538035015
2006	37.40476244730546
2007	37.4038813565759
2008	37.40300026584634
2009	37.40211917511678
2010	37.401238084387224
2011	37.40009114731685
2012	37.398944210246476
2013	37.3977972731761
2014	37.39665033610573
2015	37.39550339903536
2016	37.39603509171699
2017	37.41160609167901
2018	37.42793665261479
2019	37.4673198891041
2020	37.570126466902124
2021	37.6306509437545