Year	% of land area
1990	3.816377171215881
1991	4.420347394540943
1992	5.0243176178660045
1993	5.628287841191066
1994	6.232258064516129
1995	6.836228287841191
1996	7.440198511166253
1997	8.044168734491315
1998	8.648138957816377
1999	9.252109181141439
2000	9.856079404466502
2001	9.930521091811414
2002	10.004962779156328
2003	10.079404466501241
2004	10.153846153846153
2005	10.228287841191067
2006	10.302729528535979
2007	10.377171215880892
2008	10.451612903225806
2009	10.526054590570718
2010	10.600496277915633
2011	10.674937965260547
2012	10.749379652605459
2013	10.823821339950372
2014	10.898263027295286
2015	10.972704714640198
2016	11.047146401985112
2017	11.121588089330023
2018	11.196029776674937
2019	11.27047146401985
2020	11.344913151364763
2021	11.419354838709678