|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 4.19 | 3.79 |
| 1987 | 4.05 | 4.05 |
| 1988 | 3.67 | 3.68 |
| 1989 | 4.05 | 4.05 |
| 1990 | 4.65 | 4.49 |
| 1991 | 3.88 | 3.70 |
| 1992 | 1.24 | 1.21 |
| 1993 | 1.29 | 1.26 |
| 1994 | 1.36 | 1.33 |
| 1995 | 1.24 | 1.26 |
| 1996 | 1.28 | 1.24 |
| 1997 | 1.29 | 1.24 |
| 1998 | | 1.22 |
| 1999 | | 1.15 |
| 2000 | .93 | .93 |
| 2001 | 1.15 | .82 |
| 2002 | .96 | .96 |
| 2003 | 1.24 | 1.24 |
| 2004 | 1.15 | 1.38 |
| 2005 | 1.10 | 1.57 |
| 2006 | 1.24 | 1.96 |
| 2007 | 1.47 | 2.13 |
| 2008 | 1.08 | 2.31 |
| 2009 | 1.57 | 2.38 |
| 2010 | 2.29 | 3.32 |
|
|