Year % of land area 1961 10.869565217391305 1962 10.869565217391305 1963 10.869565217391305 1964 10.869565217391305 1965 10.869565217391305 1966 10.869565217391305 1967 10.869565217391305 1968 10.869565217391305 1969 10.869565217391305 1970 10.869565217391305 1971 10.869565217391305 1972 10.869565217391305 1973 10.869565217391305 1974 10.869565217391305 1975 10.869565217391305 1976 10.869565217391305 1977 10.869565217391305 1978 10.869565217391305 1979 10.869565217391305 1980 10.869565217391305 1981 10.869565217391305 1982 13.043478260869565 1983 13.043478260869565 1984 13.043478260869565 1985 13.043478260869565 1986 13.043478260869565 1987 13.043478260869565 1988 10.869565217391305 1989 10.869565217391305 1990 8.695652173913043 1991 8.695652173913043 1992 8.695652173913043 1993 8.695652173913043 1994 8.695652173913043 1995 8.695652173913043 1996 8.695652173913043 1997 8.695652173913043 1998 8.695652173913043 1999 8.695652173913043 2000 8.695652173913043 2001 8.695652173913043 2002 8.695652173913043 2003 8.695652173913043 2004 8.695652173913043 2005 8.695652173913043 2006 8.695652173913043 2007 6.521739130434782 2008 6.521739130434782 2009 6.304347826086956 2010 5.217391304347826 2011 3.260869565217391 2012 3.260869565217391 2013 3.369565217391304 2014 3.369565217391304 2015 3.369565217391304 2016 3.369565217391304 2017 3.369565217391304 2018 3.369565217391304 2019 3.369565217391304 2020 3.369565217391304 2021 3.369565217391304