|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 6.31 | 5.14 |
| 1987 | 6.89 | 7.45 |
| 1988 | 7.25 | 9.56 |
| 1989 | 8.68 | 8.50 |
| 1990 | 8.82 | 5.76 |
| 1991 | 5.54 | 3.65 |
| 1992 | 5.64 | 3.09 |
| 1993 | 7.60 | 3.59 |
| 1994 | 9.82 | 3.23 |
| 1995 | 11.03 | 3.30 |
| 1996 | 11.98 | 3.64 |
| 1997 | 14.38 | 3.82 |
| 1998 | 15.35 | 3.80 |
| 1999 | 15.77 | 3.90 |
| 2000 | 12.91 | 3.92 |
| 2001 | 11.22 | 2.83 |
| 2002 | 11.38 | 3.76 |
| 2003 | 8.39 | 1.78 |
| 2004 | 13.73 | 2.59 |
| 2005 | 11.54 | 4.21 |
| 2006 | 14.14 | 3.25 |
| 2007 | 13.18 | 2.50 |
| 2008 | 10.89 | 3.06 |
| 2009 | 10.10 | 2.85 |
| 2010 | 9.16 | 2.50 |
|
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