Year	% of land area
1961	9.65
1962	9.65
1963	9.65
1964	9.65
1965	9.65
1966	9.65
1967	9.65
1968	9.65
1969	9.65
1970	9.65
1971	9.65
1972	9.65
1973	9.65
1974	9.65
1975	9.65
1976	9.65
1977	9.65
1978	9.65
1979	9.65
1980	9.65
1981	9.65
1982	9.65
1983	9.65
1984	9.65
1985	9.65
1986	9.65
1987	9.65
1988	9.65
1989	9.65
1990	9.65
1991	9.82
1992	9.99
1993	10.16
1994	10.33
1995	10.5
1996	10.67
1997	10.84
1998	11.01
1999	11.18
2000	11.35
2001	11.5
2002	11.65
2003	11.799999999999999
2004	11.95
2005	12.1
2006	12.25
2007	12.4
2008	12.55
2009	12.7
2010	12.85
2011	13
2012	13.15
2013	13.3
2014	13.450000000000001
2015	13.600000000000001
2016	13.750000000000002
2017	13.900000000000002
2018	14.05
2019	14.2
2020	14.35
2021	14.499999999999998