|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 4.26 | 2.26 |
| 1987 | 2.40 | 2.40 |
| 1988 | 2.21 | 2.31 |
| 1989 | 2.14 | 2.44 |
| 1990 | 2.53 | 2.53 |
| 1991 | 2.95 | 2.95 |
| 1992 | 3.08 | 3.48 |
| 1993 | 3.02 | 3.02 |
| 1994 | 1.97 | 2.47 |
| 1995 | 2.24 | 2.24 |
| 1996 | 1.98 | 1.98 |
| 1997 | 2.14 | 2.14 |
| 1998 | 2.11 | 2.37 |
| 1999 | 1.50 | 2.54 |
| 2000 | 1.18 | 2.72 |
| 2001 | 2.34 | 2.25 |
| 2002 | 2.37 | 2.75 |
| 2003 | 1.62 | 1.73 |
| 2004 | 1.68 | 1.79 |
| 2005 | 1.49 | 2.91 |
| 2006 | 1.02 | 1.95 |
| 2007 | 1.02 | 1.75 |
| 2008 | 1.11 | 1.82 |
| 2009 | 1.38 | 2.15 |
| 2010 | 1.08 | 1.23 |
|
|