Year	% of land area
1990	64.29866599546942
1991	63.65577397432671
1992	63.012881953183985
1993	62.36998993204128
1994	61.727097910898564
1995	61.08420588975585
1996	60.441313868613136
1997	59.79842184747043
1998	59.155529826327715
1999	58.512637805184994
2000	57.86974578404228
2001	57.008572866851246
2002	56.147399949660205
2003	55.28622703246916
2004	54.42505411527813
2005	53.56388119808708
2006	52.70270828089605
2007	51.84153536370501
2008	50.98036244651397
2009	50.119189529322924
2010	49.2580166121319
2011	48.21534356909137
2012	47.172670526050844
2013	46.12999748301032
2014	45.0873244399698
2015	44.04465139692927
2016	43.62730933803171
2017	42.638484772212436
2018	41.93538887490561
2019	41.2323181474956
2020	40.529222250188774
2021	39.826143216712815