|
| year | production | consumption |
| 1980 | 27.00 | 25.00 |
| 1981 | 22.00 | 26.50 |
| 1982 | 24.00 | 25.10 |
| 1983 | 22.00 | 24.50 |
| 1984 | 21.00 | 24.00 |
| 1985 | 20.00 | 21.52 |
| 1986 | 18.00 | 21.11 |
| 1987 | 19.00 | 21.31 |
| 1988 | 19.00 | 23.11 |
| 1989 | 20.00 | 24.34 |
| 1990 | 20.92 | 25.18 |
| 1991 | 21.00 | 25.59 |
| 1992 | 21.27 | 26.28 |
| 1993 | 22.24 | 27.43 |
| 1994 | 22.60 | 30.45 |
| 1995 | 28.00 | 32.71 |
| 1996 | 30.14 | 34.79 |
| 1997 | 29.20 | 36.45 |
| 1998 | 34.60 | 40.41 |
| 1999 | 32.40 | 43.47 |
| 2000 | 29.92 | 48.10 |
| 2001 | 34.34 | 46.74 |
| 2002 | 32.16 | 46.72 |
| 2003 | 29.33 | 46.26 |
| 2004 | 47.64 | 49.62 |
| 2005 | 50.73 | 50.80 |
| 2006 | 48.90 | 58.05 |
| 2007 | 49.18 | 59.69 |
| 2008 | 38.88 | 61.61 |
| 2009 | 33.78 | 50.53 |
| 2010 | 34.54 | 54.35 |
| 2011 | 35.52 | 62.00 |
|
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