|
| year | production | consumption |
| 1980 | | 40.00 |
| 1981 | | 36.40 |
| 1982 | | 34.40 |
| 1983 | | 27.40 |
| 1984 | | 26.00 |
| 1985 | | 24.31 |
| 1986 | | 23.28 |
| 1987 | | 26.60 |
| 1988 | | 33.29 |
| 1989 | | 32.04 |
| 1990 | | 31.19 |
| 1991 | | 29.52 |
| 1992 | | 31.94 |
| 1993 | | 34.88 |
| 1994 | | 33.28 |
| 1995 | | 30.96 |
| 1996 | | 34.15 |
| 1997 | | 37.11 |
| 1998 | | 44.18 |
| 1999 | | 48.38 |
| 2000 | | 43.18 |
| 2001 | | 34.11 |
| 2002 | | 37.04 |
| 2003 | | 36.69 |
| 2004 | | 38.47 |
| 2005 | | 40.14 |
| 2006 | | 46.80 |
| 2007 | | 45.30 |
| 2008 | | 59.51 |
| 2009 | | 59.28 |
| 2010 | | 55.91 |
| 2011 | | 40.00 |
|
|