|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 4.53 | 4.27 |
| 1987 | 4.54 | 4.77 |
| 1988 | 4.98 | 5.06 |
| 1989 | 4.98 | 5.31 |
| 1990 | 5.07 | 5.07 |
| 1991 | 5.86 | 5.41 |
| 1992 | 4.89 | 6.05 |
| 1993 | 1.63 | 6.69 |
| 1994 | | 7.68 |
| 1995 | 5.96 | 7.02 |
| 1996 | 5.75 | 8.45 |
| 1997 | 7.09 | 8.91 |
| 1998 | 8.13 | 8.11 |
| 1999 | 7.20 | 8.13 |
| 2000 | 7.46 | 7.03 |
| 2001 | 7.02 | 6.49 |
| 2002 | 5.05 | 5.14 |
| 2003 | 7.48 | 5.82 |
| 2004 | 12.12 | 4.92 |
| 2005 | 12.53 | 5.87 |
| 2006 | 9.09 | 4.51 |
| 2007 | 8.13 | 5.80 |
| 2008 | 10.49 | 6.95 |
| 2009 | 9.11 | 6.52 |
| 2010 | 10.38 | 9.23 |
|
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