|
| year | production | consumption |
| 1980 | | 12.00 |
| 1981 | | 12.00 |
| 1982 | | 13.00 |
| 1983 | | 15.00 |
| 1984 | | 15.00 |
| 1985 | | 18.00 |
| 1986 | | 17.09 |
| 1987 | | 19.44 |
| 1988 | | 18.69 |
| 1989 | | 19.77 |
| 1990 | | 19.73 |
| 1991 | | 16.43 |
| 1992 | | 23.49 |
| 1993 | | 21.89 |
| 1994 | | 13.98 |
| 1995 | | 15.45 |
| 1996 | | 11.56 |
| 1997 | | 11.59 |
| 1998 | | 17.14 |
| 1999 | | 21.25 |
| 2000 | | 22.73 |
| 2001 | | 23.31 |
| 2002 | | 25.64 |
| 2003 | | 27.55 |
| 2004 | | 28.59 |
| 2005 | | 29.81 |
| 2006 | | 33.71 |
| 2007 | | 37.33 |
| 2008 | | 46.99 |
| 2009 | | 45.60 |
| 2010 | | 42.33 |
| 2011 | | 44.00 |
|
|