|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 4.07 | 7.26 |
| 1987 | 4.42 | 8.00 |
| 1988 | 3.54 | 7.59 |
| 1989 | 4.14 | 8.74 |
| 1990 | 3.86 | 7.16 |
| 1991 | 1.98 | 5.91 |
| 1992 | 4.18 | 8.36 |
| 1993 | 4.30 | 8.59 |
| 1994 | | 4.59 |
| 1995 | | 6.24 |
| 1996 | | 6.26 |
| 1997 | | 6.27 |
| 1998 | | 6.27 |
| 1999 | | 10.57 |
| 2000 | | 11.41 |
| 2001 | | 12.45 |
| 2002 | | 13.37 |
| 2003 | | 14.27 |
| 2004 | .00 | 14.70 |
| 2005 | | 14.80 |
| 2006 | | 18.25 |
| 2007 | | 22.50 |
| 2008 | | 29.59 |
| 2009 | | 26.73 |
| 2010 | | 23.61 |
|
|