Year	% of land area
1993	43.12152193606833
1994	42.92739743755662
1995	42.720331305810795
1996	42.15089944350977
1997	42.06030801087097
1998	42.20266597644623
1999	42.13795781027566
2000	41.96971657823217
2001	41.87912514559338
2002	35.97372848453475
2003	35.70958975022648
2004	35.34157390629045
2005	35.1076883251359
2006	34.14161812297735
2007	33.99715210355987
2008	33.66442257897462
2009	33.426721905748316
2010	32.99145409814839
2011	32.650653890975015
2012	32.61426906642497
2013	32.38798238798239
2014	32.23258223258224
2015	32.2497085869706
2016	32.26266027716617
2017	32.327418728144025
2018	32.17199844579718
2019	32.179987177079354
2020	32.17877335229052
2021	32.06939577645564