Year	% of land area
1961	5.283018867924529
1962	5.283018867924529
1963	5.283018867924529
1964	5.283018867924529
1965	5.283018867924529
1966	5.283018867924529
1967	5.345911949685535
1968	5.345911949685535
1969	5.345911949685535
1970	5.345911949685535
1971	5.345911949685535
1972	5.377358490566038
1973	5.471698113207547
1974	5.581761006289308
1975	5.7075471698113205
1976	5.786163522012579
1977	5.911949685534592
1978	6.0062893081761
1979	6.053459119496855
1980	6.147798742138365
1981	6.19496855345912
1982	6.2578616352201255
1983	6.39622641509434
1984	7.235849056603774
1985	7.484276729559748
1986	7.484276729559748
1987	7.547169811320755
1988	7.610062893081761
1989	7.610062893081761
1990	7.641509433962264
1991	7.70440251572327
1992	8.176100628930817
1993	9.125786163522012
1994	9.433962264150944
1995	9.433962264150944
1996	9.433962264150944
1997	9.119496855345911
1998	9.119496855345911
1999	8.80503144654088
2000	8.80503144654088
2001	8.80503144654088
2002	8.80503144654088
2003	8.80503144654088
2004	8.80503144654088
2005	8.80503144654088
2006	8.80503144654088
2007	9.119496855345911
2008	9.119496855345911
2009	9.119496855345911
2010	9.119496855345911
2011	9.119496855345911
2012	9.433962264150944
2013	11.0062893081761
2014	11.0062893081761
2015	11.0062893081761
2016	11.0062893081761
2017	11.0062893081761
2018	11.0062893081761
2019	11.0062893081761
2020	11.0062893081761
2021	11.0062893081761