|
| year | production | consumption |
| 1980 | 20.00 | 19.10 |
| 1981 | 20.00 | 20.40 |
| 1982 | 23.00 | 21.40 |
| 1983 | 25.00 | 21.30 |
| 1984 | 32.00 | 19.50 |
| 1985 | 33.00 | 18.90 |
| 1986 | 32.00 | 20.54 |
| 1987 | 32.00 | 18.53 |
| 1988 | 30.00 | 23.34 |
| 1989 | 28.00 | 21.95 |
| 1990 | 29.00 | 20.42 |
| 1991 | 28.00 | 21.52 |
| 1992 | 26.00 | 24.27 |
| 1993 | 25.00 | 25.37 |
| 1994 | 26.00 | 19.97 |
| 1995 | 30.00 | 20.55 |
| 1996 | 30.00 | 21.32 |
| 1997 | 28.33 | 20.92 |
| 1998 | 26.38 | 19.79 |
| 1999 | 22.20 | 16.93 |
| 2000 | 26.00 | 14.16 |
| 2001 | 24.00 | 9.53 |
| 2002 | 22.67 | 8.09 |
| 2003 | 22.00 | 8.13 |
| 2004 | 21.08 | 11.32 |
| 2005 | 19.75 | 11.60 |
| 2006 | 20.00 | 11.26 |
| 2007 | 22.16 | 12.97 |
| 2008 | 19.96 | 11.50 |
| 2009 | 22.00 | 11.49 |
| 2010 | 21.00 | 14.71 |
| 2011 | 20.16 | 10.00 |
|
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