Year	sq. km
1961	252000
1962	252050
1963	252100
1964	252150
1965	252200
1966	252250
1967	252300
1968	252350
1969	252400
1970	252450
1971	252500
1972	252550
1973	252600
1974	252650
1975	255720
1976	255780
1977	255800
1978	255800
1979	255800
1980	255800
1981	255800
1982	255800
1983	255800
1984	255050
1985	263540
1986	263730
1987	264350
1988	266620
1989	270530
1990	267700
1991	268770
1992	270720
1993	268400
1994	272320
1995	272180
1996	264510
1997	265940
1998	264580
1999	268760
2000	266710
2001	268390
2002	268180
2003	268740
2004	269920
2005	270020
2006	270540
2007	270700
2008	270850
2009	272850
2010	273100
2011	276210
2012	276320
2013	276430
2014	276540
2015	276660
2016	276770
2017	276880
2018	276990
2019	277100
2020	277100
2021	277100