|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | .74 |
| 1987 | | .74 |
| 1988 | | .78 |
| 1989 | | .78 |
| 1990 | | .78 |
| 1991 | | .80 |
| 1992 | | .83 |
| 1993 | | .83 |
| 1994 | | .85 |
| 1995 | | .55 |
| 1996 | | .57 |
| 1997 | | .61 |
| 1998 | | .49 |
| 1999 | | .78 |
| 2000 | | .64 |
| 2001 | | .61 |
| 2002 | | .74 |
| 2003 | | .89 |
| 2004 | | 1.00 |
| 2005 | | 1.14 |
| 2006 | | 1.46 |
| 2007 | | 1.48 |
| 2008 | | 1.50 |
| 2009 | | 1.52 |
| 2010 | | 1.65 |
|
|