Year	% of land area
1993	34.05954445451016
1994	34.069729519865405
1995	34.079914585220656
1996	34.0900996505759
1997	34.10028471593115
1998	34.1104697812864
1999	34.12065484664165
2000	34.130839911996894
2001	34.15683965316423
2002	34.182839394331566
2003	34.2088391354989
2004	34.239269997411334
2005	34.265273103805335
2006	34.295715210355986
2007	34.321721682847894
2008	34.352175038839974
2009	34.3781848783014
2010	34.40864948854072
2011	34.43716172471837
2012	34.46567396089603
2013	34.4986531986532
2014	34.527169127169124
2015	34.560160600958426
2016	34.57907006864396
2017	34.602512627897944
2018	34.625955187151924
2019	34.65141732130483
2020	34.67799192549392
2021	34.70669802089294