|
| year | production | consumption |
| 1980 | | 27.60 |
| 1981 | | 29.10 |
| 1982 | | 24.90 |
| 1983 | | 18.50 |
| 1984 | | 16.80 |
| 1985 | | 15.30 |
| 1986 | | 15.19 |
| 1987 | | 16.76 |
| 1988 | | 15.95 |
| 1989 | | 18.10 |
| 1990 | | 19.14 |
| 1991 | | 17.17 |
| 1992 | | 14.63 |
| 1993 | | 15.54 |
| 1994 | | 16.94 |
| 1995 | | 19.61 |
| 1996 | | 22.05 |
| 1997 | | 21.99 |
| 1998 | | 24.56 |
| 1999 | | 22.29 |
| 2000 | | 22.22 |
| 2001 | | 21.84 |
| 2002 | | 22.26 |
| 2003 | | 26.60 |
| 2004 | | 26.96 |
| 2005 | | 30.73 |
| 2006 | | 30.86 |
| 2007 | | 29.38 |
| 2008 | | 20.26 |
| 2009 | | 22.83 |
| 2010 | | 22.83 |
| 2011 | | 41.00 |
|
|