|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | |
| 1987 | | 3.20 |
| 1988 | | 3.25 |
| 1989 | | 3.37 |
| 1990 | | 3.41 |
| 1991 | | 3.54 |
| 1992 | | 3.77 |
| 1993 | | 3.74 |
| 1994 | | 3.47 |
| 1995 | | 3.74 |
| 1996 | | 3.53 |
| 1997 | | 3.80 |
| 1998 | | 4.15 |
| 1999 | | 4.20 |
| 2000 | | 1.72 |
| 2001 | | 1.96 |
| 2002 | | 4.25 |
| 2003 | | 5.14 |
| 2004 | | 4.62 |
| 2005 | | 4.91 |
| 2006 | | 1.96 |
| 2007 | | 2.45 |
| 2008 | | 2.01 |
| 2009 | | 3.58 |
| 2010 | | 3.58 |
|
|