|
| year | production | consumption |
| 1984 | 34.61 | 54.19 |
| 1985 | 42.55 | 49.01 |
| 1986 | 35.85 | 50.20 |
| 1987 | 32.88 | 48.28 |
| 1988 | 31.83 | 39.16 |
| 1989 | 28.19 | 35.44 |
| 1990 | 30.54 | 39.51 |
| 1991 | 32.04 | 39.29 |
| 1992 | 32.13 | 34.26 |
| 1993 | 29.76 | 37.28 |
| 1994 | 25.98 | 34.63 |
| 1995 | 24.89 | 33.50 |
| 1996 | 25.05 | 32.15 |
| 1997 | 27.18 | 34.22 |
| 1998 | 23.81 | 34.67 |
| 1999 | 23.12 | 28.41 |
| 2000 | 17.24 | 23.52 |
| 2001 | 22.88 | 26.28 |
| 2002 | 18.93 | 19.27 |
| 2003 | 20.66 | 22.25 |
| 2004 | 20.62 | 20.84 |
| 2005 | 21.70 | 19.29 |
| 2006 | 18.36 | 19.34 |
| 2007 | 17.09 | 16.13 |
| 2008 | 14.20 | 14.36 |
| 2009 | 16.03 | 13.30 |
| 2010 | 17.94 | 16.35 |
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