Year	% of land area
1990	48.3205734171298
1991	48.08684360878824
1992	47.85311380044669
1993	47.61938399210513
1994	47.38565418376357
1995	47.15192437542201
1996	46.918194567080455
1997	46.684464758738905
1998	46.45073495039734
1999	46.21700514205579
2000	45.98327533371423
2001	45.78330649768868
2002	45.58333766166312
2003	45.38336882563757
2004	45.18339998961201
2005	44.98343115358646
2006	44.783462317560904
2007	44.58349348153535
2008	44.383524645509794
2009	44.18355580948424
2010	43.983586973458685
2011	43.77582714382174
2012	43.5680673141848
2013	43.36030748454787
2014	43.152547654910926
2015	42.94478782527399
2016	42.73702799563704
2017	42.52926816600011
2018	42.321508336363166
2019	42.11374850672623
2020	41.90598867708929
2021	41.69822884745235