|
| year | production | consumption |
| 1984 | .61 | .57 |
| 1985 | .85 | .72 |
| 1986 | .65 | .63 |
| 1987 | .55 | .57 |
| 1988 | .48 | .40 |
| 1989 | .33 | .28 |
| 1990 | .50 | .25 |
| 1991 | .11 | .29 |
| 1992 | .28 | .34 |
| 1993 | .22 | .24 |
| 1994 | .54 | .33 |
| 1995 | .31 | .24 |
| 1996 | .65 | .20 |
| 1997 | .52 | .22 |
| 1998 | 1.32 | .26 |
| 1999 | .17 | .28 |
| 2000 | .20 | .30 |
| 2001 | .26 | .35 |
| 2002 | .57 | .26 |
| 2003 | .42 | .37 |
| 2004 | .63 | .33 |
| 2005 | .89 | .35 |
| 2006 | .74 | .42 |
| 2007 | .56 | .20 |
| 2008 | .43 | .17 |
| 2009 | 1.16 | .15 |
| 2010 | .37 | .15 |
|
|