|
| year | production | consumption |
| 1984 | | 4.36 |
| 1985 | | 4.93 |
| 1986 | | 5.27 |
| 1987 | | 5.83 |
| 1988 | | 5.89 |
| 1989 | | 6.25 |
| 1990 | | 6.32 |
| 1991 | | 5.69 |
| 1992 | | 6.09 |
| 1993 | | 6.61 |
| 1994 | | 6.58 |
| 1995 | | 6.83 |
| 1996 | | 7.63 |
| 1997 | | 7.56 |
| 1998 | | 7.67 |
| 1999 | | 8.09 |
| 2000 | | 8.21 |
| 2001 | | 7.25 |
| 2002 | | 8.19 |
| 2003 | | 8.48 |
| 2004 | | 9.17 |
| 2005 | | 8.77 |
| 2006 | | 8.03 |
| 2007 | | 7.95 |
| 2008 | | 8.34 |
| 2009 | | 7.05 |
| 2010 | | 6.72 |
|
|