|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 3.52 | 4.99 |
| 1987 | 1.68 | 3.17 |
| 1988 | 1.63 | 3.20 |
| 1989 | 1.68 | 3.29 |
| 1990 | 1.70 | 3.27 |
| 1991 | .89 | 1.85 |
| 1992 | .71 | 1.53 |
| 1993 | .71 | 1.63 |
| 1994 | .71 | 1.63 |
| 1995 | .71 | 1.63 |
| 1996 | .71 | 1.63 |
| 1997 | .71 | 1.63 |
| 1998 | .71 | 1.63 |
| 1999 | .71 | 1.63 |
| 2000 | | 1.50 |
| 2001 | | 1.50 |
| 2002 | | 1.50 |
| 2003 | | 1.50 |
| 2004 | | 1.50 |
| 2005 | | 1.78 |
| 2006 | .21 | 1.80 |
| 2007 | .22 | 2.17 |
| 2008 | .22 | 2.21 |
| 2009 | | 2.17 |
| 2010 | | 2.17 |
|
|