|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 1.46 | 1.31 |
| 1987 | 1.21 | 1.20 |
| 1988 | 1.55 | 1.56 |
| 1989 | 1.46 | 1.35 |
| 1990 | 1.16 | 1.07 |
| 1991 | 1.15 | 1.16 |
| 1992 | 1.32 | 1.38 |
| 1993 | 1.66 | 1.68 |
| 1994 | 1.25 | 1.28 |
| 1995 | .96 | .98 |
| 1996 | .93 | 1.02 |
| 1997 | .68 | .96 |
| 1998 | .96 | 1.64 |
| 1999 | 1.10 | 1.64 |
| 2000 | 1.02 | 1.02 |
| 2001 | .30 | .30 |
| 2002 | | .20 |
| 2003 | | .06 |
| 2004 | | .00 |
| 2005 | | .00 |
| 2006 | | |
| 2007 | | |
| 2008 | | .39 |
| 2009 | | .32 |
| 2010 | | .50 |
|
|