|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | |
| 1987 | | |
| 1988 | | |
| 1989 | | |
| 1990 | | |
| 1991 | | |
| 1992 | .92 | 8.57 |
| 1993 | .74 | 9.58 |
| 1994 | .28 | 9.13 |
| 1995 | | 5.80 |
| 1996 | | 8.43 |
| 1997 | | 9.04 |
| 1998 | | 9.67 |
| 1999 | .25 | 6.83 |
| 2000 | .04 | 2.69 |
| 2001 | .04 | 13.18 |
| 2002 | .04 | 2.43 |
| 2003 | .04 | 1.87 |
| 2004 | .05 | 2.06 |
| 2005 | | 2.41 |
| 2006 | | 5.53 |
| 2007 | | 5.49 |
| 2008 | | 4.20 |
| 2009 | | 4.23 |
| 2010 | | 3.87 |
|
|