|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | |
| 1987 | .82 | .85 |
| 1988 | .92 | 1.87 |
| 1989 | .92 | .92 |
| 1990 | .71 | 2.04 |
| 1991 | .83 | 1.77 |
| 1992 | .89 | 2.23 |
| 1993 | .93 | 2.24 |
| 1994 | .95 | 1.52 |
| 1995 | .95 | 1.52 |
| 1996 | .95 | 1.52 |
| 1997 | .97 | 1.57 |
| 1998 | .97 | 1.57 |
| 1999 | 1.00 | 1.59 |
| 2000 | | 1.67 |
| 2001 | | 2.46 |
| 2002 | | 2.60 |
| 2003 | | 2.80 |
| 2004 | | 2.98 |
| 2005 | | 3.20 |
| 2006 | | 3.39 |
| 2007 | | 3.64 |
| 2008 | | 3.94 |
| 2009 | | 4.15 |
| 2010 | | 3.35 |
|
|