|
| year | production | consumption |
| 1984 | .11 | .24 |
| 1985 | .13 | .23 |
| 1986 | .09 | .23 |
| 1987 | .07 | .24 |
| 1988 | .13 | .19 |
| 1989 | .31 | .28 |
| 1990 | .42 | .36 |
| 1991 | .26 | .67 |
| 1992 | .15 | .64 |
| 1993 | .07 | .30 |
| 1994 | .09 | .04 |
| 1995 | -.02 | .12 |
| 1996 | | .26 |
| 1997 | | .23 |
| 1998 | | .37 |
| 1999 | | .33 |
| 2000 | | .13 |
| 2001 | .91 | .02 |
| 2002 | 1.08 | .08 |
| 2003 | 1.23 | .10 |
| 2004 | 1.27 | .10 |
| 2005 | .43 | .10 |
| 2006 | 1.29 | .07 |
| 2007 | .56 | .07 |
| 2008 | 1.06 | .07 |
| 2009 | 1.38 | .03 |
| 2010 | 1.38 | .03 |
|
|