|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | .35 | .92 |
| 1987 | 1.12 | 1.72 |
| 1988 | 1.24 | 1.38 |
| 1989 | .68 | 1.24 |
| 1990 | 1.11 | 1.32 |
| 1991 | 1.19 | 1.38 |
| 1992 | .86 | 1.70 |
| 1993 | .89 | 1.73 |
| 1994 | .89 | 1.78 |
| 1995 | .96 | 1.82 |
| 1996 | .98 | 1.84 |
| 1997 | .98 | 1.85 |
| 1998 | .98 | 1.85 |
| 1999 | .98 | 1.85 |
| 2000 | 2.28 | 3.22 |
| 2001 | 2.57 | 3.55 |
| 2002 | 2.62 | 3.55 |
| 2003 | 2.62 | 3.55 |
| 2004 | 2.63 | 3.57 |
| 2005 | 3.32 | 4.16 |
| 2006 | | 3.62 |
| 2007 | | 2.69 |
| 2008 | | 1.70 |
| 2009 | | 1.79 |
| 2010 | | 1.79 |
|
|