|
| year | production | consumption |
| 1984 | 31.36 | 29.92 |
| 1985 | 33.16 | 30.93 |
| 1986 | 38.80 | 32.58 |
| 1987 | 39.10 | 34.87 |
| 1988 | 41.90 | 36.45 |
| 1989 | 37.99 | 40.52 |
| 1990 | 40.65 | 41.44 |
| 1991 | 36.05 | 36.28 |
| 1992 | 36.94 | 33.78 |
| 1993 | 29.59 | 34.45 |
| 1994 | 28.85 | 33.45 |
| 1995 | 33.29 | 33.04 |
| 1996 | 32.55 | 31.06 |
| 1997 | 37.95 | 31.32 |
| 1998 | 38.92 | 32.09 |
| 1999 | 35.03 | 32.46 |
| 2000 | 34.31 | 30.84 |
| 2001 | 36.88 | 32.20 |
| 2002 | 36.37 | 32.99 |
| 2003 | 34.04 | 32.97 |
| 2004 | 33.52 | 33.29 |
| 2005 | 30.65 | 34.40 |
| 2006 | 31.49 | 35.35 |
| 2007 | 32.25 | 36.46 |
| 2008 | 30.75 | 36.13 |
| 2009 | 30.35 | 36.24 |
| 2010 | 28.16 | 31.90 |
|
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