Year | Million km2 |
---|---|
1979 | 1.1 |
1980 | 3.3 |
1981 | 3.1 |
1982 | 10.8 |
1983 | 12.2 |
1984 | 14.7 |
1985 | 18.8 |
1986 | 14.4 |
1987 | 22.4 |
1988 | 13.8 |
1989 | 21.7 |
1990 | 21.1 |
1991 | 22.6 |
1992 | 24.9 |
1993 | 25.8 |
1994 | 25.2 |
1996 | 26.9 |
1997 | 25.1 |
1998 | 27.9 |
1999 | 25.8 |
2000 | 29.9 |
2001 | 26.5 |
2002 | 21.9 |
2003 | 28.4 |
2004 | 22.8 |
2005 | 27.3 |
2006 | 29.6 |
2007 | 25.2 |
2008 | 27 |
2009 | 24.4 |
2010 | 22.6 |
2011 | 26.1 |
2012 | 21.1 |
2013 | 24 |
2014 | 24.1 |
2015 | 28.2 |
2016 | 23.0 |