|
| year | production | consumption |
| 1980 | | 14.20 |
| 1981 | | 12.20 |
| 1982 | | 11.00 |
| 1983 | | |
| 1984 | | 6.70 |
| 1985 | | 8.58 |
| 1986 | | 8.51 |
| 1987 | | 7.16 |
| 1988 | | 7.93 |
| 1989 | | 8.70 |
| 1990 | 3.90 | 10.54 |
| 1991 | 3.50 | 9.73 |
| 1992 | | 9.20 |
| 1993 | | 9.62 |
| 1994 | | 9.42 |
| 1995 | | 9.73 |
| 1996 | 7.50 | 9.54 |
| 1997 | | 9.82 |
| 1998 | | 9.92 |
| 1999 | 10.00 | 9.92 |
| 2000 | 10.00 | 10.33 |
| 2001 | 10.00 | 10.88 |
| 2002 | 10.00 | 11.46 |
| 2003 | 10.00 | 11.73 |
| 2004 | 10.00 | 12.22 |
| 2005 | 10.00 | 12.58 |
| 2006 | 11.60 | 12.94 |
| 2007 | 13.54 | 12.78 |
| 2008 | 15.84 | 12.78 |
| 2009 | 16.00 | 13.14 |
| 2010 | 16.00 | 12.90 |
| 2011 | 16.00 | 15.00 |
|
|