Year	% of land area
1961	0.9031384059607135
1962	1.0724768570783474
1963	1.0160307067058025
1964	1.1289230074508918
1965	1.1289230074508918
1966	1.1289230074508918
1967	1.1289230074508918
1968	1.1289230074508918
1969	1.1289230074508918
1970	1.1289230074508918
1971	1.1289230074508918
1972	1.1289230074508918
1973	1.1289230074508918
1974	1.1289230074508918
1975	1.1289230074508918
1976	1.1289230074508918
1977	1.1289230074508918
1978	1.1289230074508918
1979	1.1289230074508918
1980	1.1289230074508918
1981	1.1289230074508918
1982	1.1289230074508918
1983	1.1289230074508918
1984	1.1289230074508918
1985	1.1289230074508918
1986	1.1289230074508918
1987	1.1289230074508918
1988	1.1289230074508918
1989	1.1289230074508918
1990	1.1289230074508918
1991	1.1289230074508918
1992	1.1289230074508918
1993	1.1289230074508918
1994	1.1289230074508918
1995	1.1289230074508918
1996	1.1289230074508918
1997	1.2361706931587266
1998	1.4393768344998872
1999	1.4675999096861594
2000	1.5804922104312484
2001	1.7724091216979
2002	1.806276811921427
2003	1.9530368028900429
2004	1.8740121923684805
2005	1.8740121923684805
2006	1.8740121923684805
2007	1.8627229622939716
2008	1.8612553623842854
2009	1.896139083314518
2010	1.9310228042447506
2011	1.965906525174983
2012	2.0007902461052156
2013	2.0356739670354482
2014	2.070557687965681
2015	2.105441408895913
2016	2.140325129826146
2017	2.1752088507563787
2018	2.210092571686611
2019	2.2449762926168435
2020	2.2789568751411156
2021	2.2789568751411156