Year	% of land area
1992	10.517160319699107
1993	10.510108133521392
1994	10.503055947343677
1995	10.519511048425013
1996	10.521861777150916
1997	10.524212505876822
1998	10.526563234602728
1999	10.528913963328632
2000	10.276054270411615
2001	10.279621298843113
2002	10.286503437628323
2003	10.197831039490499
2004	10.10891286741172
2005	10.019525110760837
2006	9.930021796489617
2007	9.83751697309993
2008	9.748444262983208
2009	9.65947539253805
2010	9.571178181751442
2011	9.483512272578125
2012	9.394217530977512
2013	9.304961804910175
2014	9.279720231579962
2015	9.171584203359055
2016	9.158834383816284
2017	9.138696469263802
2018	9.123737196058894
2019	9.155497043501946
2020	9.129694769091115
2021	9.113974033990464