|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 1.14 | 1.20 |
| 1987 | 1.29 | 1.13 |
| 1988 | 1.23 | 1.16 |
| 1989 | 1.12 | 1.09 |
| 1990 | 1.12 | 1.12 |
| 1991 | 1.21 | 1.02 |
| 1992 | 1.40 | 1.03 |
| 1993 | .34 | .95 |
| 1994 | | .95 |
| 1995 | 1.13 | .94 |
| 1996 | 1.69 | 1.60 |
| 1997 | .44 | .52 |
| 1998 | .51 | .51 |
| 1999 | .55 | .49 |
| 2000 | .59 | .46 |
| 2001 | .49 | .36 |
| 2002 | .28 | .30 |
| 2003 | .23 | .21 |
| 2004 | .19 | .19 |
| 2005 | .19 | .19 |
| 2006 | .17 | .15 |
| 2007 | .19 | .17 |
| 2008 | .14 | .17 |
| 2009 | .15 | .17 |
| 2010 | .17 | .17 |
|
|