Year	% of land area
1990	6.099815157116451
1991	6.196857670979667
1992	6.293900184842884
1993	6.390942698706099
1994	6.487985212569317
1995	6.585027726432532
1996	6.682070240295748
1997	6.779112754158965
1998	6.876155268022181
1999	6.973197781885397
2000	7.070240295748614
2001	7.074861367837339
2002	7.079482439926063
2003	7.084103512014788
2004	7.088724584103511
2005	7.093345656192236
2006	7.09796672828096
2007	7.102587800369687
2008	7.10720887245841
2009	7.111829944547135
2010	7.116451016635859
2011	7.218114602587801
2012	7.3197781885397415
2013	7.421441774491683
2014	7.523105360443623
2015	7.624768946395563
2016	6.469500924214418
2017	6.469500924214418
2018	6.469500924214418
2019	6.469500924214418
2020	6.469500924214418
2021	6.469500924214418