|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 3.30 | 6.20 |
| 1987 | 3.48 | 4.47 |
| 1988 | 4.28 | 3.95 |
| 1989 | 3.58 | 3.74 |
| 1990 | 4.10 | 4.53 |
| 1991 | 2.25 | 3.30 |
| 1992 | 4.21 | 6.62 |
| 1993 | 3.99 | 4.05 |
| 1994 | 6.03 | 6.30 |
| 1995 | 5.83 | 6.69 |
| 1996 | 6.02 | 6.87 |
| 1997 | 4.95 | 6.89 |
| 1998 | 6.20 | 8.28 |
| 1999 | 7.87 | 9.49 |
| 2000 | 7.95 | 10.91 |
| 2001 | 8.02 | 11.14 |
| 2002 | 7.67 | 12.21 |
| 2003 | 9.47 | 11.10 |
| 2004 | 9.60 | 11.89 |
| 2005 | 7.28 | 12.96 |
| 2006 | 2.35 | 13.80 |
| 2007 | 6.93 | 11.83 |
| 2008 | 8.36 | 5.25 |
| 2009 | 6.67 | 13.12 |
| 2010 | 6.95 | 12.61 |
|
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