Year	% of land area
1992	77.88256769090356
1993	77.60242792109257
1994	77.62598664238008
1995	77.6191922259338
1996	77.6191922259338
1997	77.64277035236938
1998	77.66636280765725
1999	77.72036474164133
2000	77.37226277372264
2001	77.22019464720195
2002	77.06812652068126
2003	76.90903559476726
2004	76.70316301703163
2005	75.98054119793251
2006	75.49407114624506
2007	75.55487990270599
2008	75.43326238978413
2009	75.15962298570994
2010	75.03805175038052
2011	74.94672754946727
2012	74.86305538648813
2013	74.84793187347933
2014	70.40754257907543
2015	70.49878345498783
2016	70.49574209245742
2017	70.45606567345698
2018	68.63553016089256
2019	68.77111467224555
2020	68.8650614573387
2021	69.00212314225053