|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | .71 |
| 1987 | | .72 |
| 1988 | .89 | .89 |
| 1989 | .79 | 1.50 |
| 1990 | .71 | .81 |
| 1991 | .71 | .81 |
| 1992 | 5.24 | 6.06 |
| 1993 | 5.33 | 6.15 |
| 1994 | 5.38 | 6.24 |
| 1995 | 5.38 | 6.22 |
| 1996 | 5.41 | 6.25 |
| 1997 | 5.47 | 6.31 |
| 1998 | 5.47 | 6.33 |
| 1999 | 5.47 | 6.33 |
| 2000 | 5.48 | 6.39 |
| 2001 | | 6.40 |
| 2002 | | 6.43 |
| 2003 | | 6.43 |
| 2004 | | 6.48 |
| 2005 | | 6.57 |
| 2006 | | 4.95 |
| 2007 | | 4.67 |
| 2008 | | .47 |
| 2009 | | .50 |
| 2010 | | .50 |
|
|