Year	% of land area
1992	14.857744994731295
1993	15.208991921320688
1994	15.279241306638566
1995	15.279241306638566
1996	15.806111696522656
1997	15.981735159817351
1998	15.981735159817351
1999	15.806111696522656
2000	15.806111696522656
2001	15.981735159817351
2002	15.981735159817351
2003	15.981735159817351
2004	15.981735159817351
2005	15.981735159817351
2006	15.90797330523358
2007	15.879873551106428
2008	15.82016157358623
2009	15.785036880927292
2010	15.753424657534246
2011	15.778011942395503
2012	15.749912188268352
2013	15.742887249736565
2014	15.718299964875307
2015	15.690200210748156
2016	15.679662802950475
2017	15.665612925886899
2018	15.651563048823322
2019	15.623463294696172
2020	15.595363540569021
2021	15.574991218826836