Year	% of land area
1992	46.27749743751479
1993	46.103345622301525
1994	46.067094510001084
1995	46.03486010607883
1996	46.00845928598894
1997	45.87513248379384
1998	45.88594333157487
1999	45.756402987650056
2000	45.61050638902035
2001	45.00009859793733
2002	44.495609602177204
2003	44.3039846962421
2004	44.163400142987456
2005	44.12003963852036
2006	44.148957142293895
2007	43.94261240703594
2008	43.94732432405792
2009	43.997476564579244
2010	43.85368305881657
2011	43.73860332166971
2012	43.35161829284521
2013	42.93177203461667
2014	42.487917112128216
2015	42.24201637615899
2016	42.035489782647254
2017	41.84483811850947
2018	41.64449699477781
2019	41.32239548690661
2020	40.797122869248206
2021	40.27593003202759