|
| year | production | consumption |
| 1984 | 8.07 | 22.73 |
| 1985 | 8.41 | 21.12 |
| 1986 | 10.17 | 30.61 |
| 1987 | 9.66 | 23.13 |
| 1988 | 8.48 | 13.38 |
| 1989 | 8.85 | 12.30 |
| 1990 | 10.96 | 16.95 |
| 1991 | 11.35 | 20.53 |
| 1992 | 12.23 | 21.60 |
| 1993 | 12.04 | 21.52 |
| 1994 | 14.52 | 25.04 |
| 1995 | 13.88 | 23.93 |
| 1996 | 13.63 | 23.31 |
| 1997 | 18.10 | 27.23 |
| 1998 | 19.44 | 32.11 |
| 1999 | 17.46 | 37.69 |
| 2000 | 20.37 | 31.70 |
| 2001 | 20.46 | 33.38 |
| 2002 | 18.89 | 27.01 |
| 2003 | 17.77 | 21.18 |
| 2004 | 17.04 | 23.67 |
| 2005 | 18.63 | 23.00 |
| 2006 | 19.46 | 22.88 |
| 2007 | 22.32 | 14.82 |
| 2008 | 20.46 | 13.07 |
| 2009 | 16.46 | 9.34 |
| 2010 | 17.12 | 7.77 |
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