|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | 3.16 |
| 1987 | | 1.12 |
| 1988 | | .71 |
| 1989 | | .72 |
| 1990 | | 2.64 |
| 1991 | | 3.13 |
| 1992 | | 2.81 |
| 1993 | | 2.84 |
| 1994 | | 2.86 |
| 1995 | | 2.88 |
| 1996 | | 2.82 |
| 1997 | | 2.86 |
| 1998 | | 2.88 |
| 1999 | | 2.88 |
| 2000 | .52 | 2.73 |
| 2001 | .77 | 2.89 |
| 2002 | .77 | 2.89 |
| 2003 | .82 | 3.15 |
| 2004 | .80 | 3.53 |
| 2005 | .80 | 3.57 |
| 2006 | .84 | 3.78 |
| 2007 | .84 | 3.78 |
| 2008 | .84 | 3.78 |
| 2009 | .84 | 3.78 |
| 2010 | .85 | 3.80 |
|
|