Year	% of land area
1992	42.99767483455554
1993	40.636737614022536
1994	41.35217313539617
1995	41.70989089608299
1996	34.565916398713824
1997	34.67309753483387
1998	36.63029869433017
1999	36.34412448578072
2000	20.90785520103019
2001	21.068822435255402
2002	21.122478179997138
2003	21.370881280823387
2004	21.0135086841541
2005	21.638910728325353
2006	21.978414695161174
2007	21.47809305982417
2008	23.03445071831892
2009	23.222071331570294
2010	23.833178471874778
2011	23.695590022157102
2012	23.783146308341077
2013	28.00550353798871
2014	26.954828103781004
2015	27.46765778000143
2016	27.624901722535917
2017	26.74933886069616
2018	26.517046672861127
2019	26.874419269530414
2020	26.894210150107217
2021	26.375982844889208