|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 12.47 | |
| 1987 | 14.83 | .05 |
| 1988 | 11.66 | .34 |
| 1989 | 4.57 | |
| 1990 | 1.02 | |
| 1991 | 1.17 | .01 |
| 1992 | 7.60 | .02 |
| 1993 | | |
| 1994 | | |
| 1995 | .10 | .60 |
| 1996 | | |
| 1997 | 1.10 | .82 |
| 1998 | 1.23 | 1.23 |
| 1999 | | |
| 2000 | .34 | .00 |
| 2001 | 1.90 | .00 |
| 2002 | 3.60 | 3.61 |
| 2003 | 4.93 | 4.97 |
| 2004 | 2.94 | 2.77 |
| 2005 | 2.95 | 2.64 |
| 2006 | 1.97 | 1.97 |
| 2007 | 2.19 | 2.53 |
| 2008 | 2.77 | 2.40 |
| 2009 | 3.84 | 3.36 |
| 2010 | | |
|
|