|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | .97 | 1.05 |
| 1987 | .43 | .43 |
| 1988 | .98 | 1.02 |
| 1989 | .34 | .42 |
| 1990 | .25 | .25 |
| 1991 | .34 | .34 |
| 1992 | .34 | .34 |
| 1993 | .32 | .35 |
| 1994 | .42 | .42 |
| 1995 | .42 | .42 |
| 1996 | | .40 |
| 1997 | .29 | .62 |
| 1998 | .51 | .65 |
| 1999 | .36 | .66 |
| 2000 | .27 | .57 |
| 2001 | .30 | .59 |
| 2002 | .32 | .57 |
| 2003 | .40 | .66 |
| 2004 | .47 | .65 |
| 2005 | .47 | .68 |
| 2006 | .34 | .68 |
| 2007 | .42 | .70 |
| 2008 | .04 | .08 |
| 2009 | | |
| 2010 | .04 | .08 |
|
|