Year	% of land area
1990	22.129701492537315
1991	22.456119402985077
1992	22.782388059701493
1993	23.108805970149255
1994	23.43507462686567
1995	23.761492537313433
1996	24.087910447761196
1997	24.41417910447761
1998	24.740597014925374
1999	25.066865671641786
2000	25.39328358208955
2001	25.501641791044776
2002	25.420444444444446
2003	25.082241630276563
2004	25.114949201741656
2005	25.22046444121916
2006	25.143515850144087
2007	25.21194244604316
2008	25.135714285714283
2009	25.239571428571434
2010	25.27122507122507
2011	24.838920454545452
2012	24.409065155807365
2013	24.015558698727013
2014	23.58984485190409
2015	23.231875881523276
2016	22.969675599435824
2017	22.626404494382022
2018	22.3109243697479
2019	21.997206703910617
2020	21.685236768802227
2021	21.434540389972145