|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | |
| 1987 | | .77 |
| 1988 | | .92 |
| 1989 | | .96 |
| 1990 | | .96 |
| 1991 | | 1.19 |
| 1992 | | 1.36 |
| 1993 | | 2.52 |
| 1994 | | 2.52 |
| 1995 | | 2.55 |
| 1996 | | 2.55 |
| 1997 | | 2.55 |
| 1998 | | 2.59 |
| 1999 | | 2.59 |
| 2000 | | 2.60 |
| 2001 | | 2.61 |
| 2002 | | 2.63 |
| 2003 | | 2.74 |
| 2004 | | 2.64 |
| 2005 | | 2.76 |
| 2006 | | 2.74 |
| 2007 | | 2.79 |
| 2008 | | 2.83 |
| 2009 | | .80 |
| 2010 | | .80 |
|
|