|
| year | production | consumption |
| 1984 | 15.62 | 19.46 |
| 1985 | 14.66 | 19.84 |
| 1986 | 14.81 | 22.02 |
| 1987 | 19.21 | 16.58 |
| 1988 | 16.27 | 16.59 |
| 1989 | 26.68 | 13.62 |
| 1990 | 19.87 | 12.53 |
| 1991 | 24.65 | 10.39 |
| 1992 | 27.17 | 9.22 |
| 1993 | 25.87 | 9.33 |
| 1994 | 28.10 | 12.19 |
| 1995 | 28.41 | 12.15 |
| 1996 | 28.67 | 14.55 |
| 1997 | 31.21 | 14.85 |
| 1998 | 33.06 | 13.49 |
| 1999 | 33.52 | 12.13 |
| 2000 | 30.05 | 10.36 |
| 2001 | 29.11 | 11.17 |
| 2002 | 26.56 | 8.45 |
| 2003 | 30.06 | 10.22 |
| 2004 | 32.50 | 10.02 |
| 2005 | 28.47 | 9.97 |
| 2006 | 34.73 | 8.93 |
| 2007 | 36.56 | 10.73 |
| 2008 | 41.73 | 8.39 |
| 2009 | 36.00 | 8.10 |
| 2010 | 33.69 | 6.47 |
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