Year	% of land area
1992	53.42898686566446
1993	53.553961330016705
1994	53.907254527320134
1995	53.94450653111744
1996	54.390328899143206
1997	55.14137736279847
1998	56.34838492273624
1999	56.736593918142795
2000	57.386356758065496
2001	57.45000242119026
2002	57.4317945241957
2003	57.525528722837926
2004	57.515240952196635
2005	57.56835228647471
2006	57.552912133789945
2007	57.56453545365429
2008	57.568349328911864
2009	57.57909515625378
2010	57.67034456058846
2011	57.69193544484502
2012	57.68709622783034
2013	57.70454517959327
2014	57.70054316925347
2015	57.70175290033026
2016	57.73557517842023
2017	57.79560136459316
2018	57.825392600479105
2019	57.82781232608222
2020	57.83824988505191
2021	57.84150030248034