|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | .75 |
| 1987 | | .75 |
| 1988 | | .77 |
| 1989 | | .77 |
| 1990 | | .77 |
| 1991 | | .78 |
| 1992 | | .80 |
| 1993 | | .80 |
| 1994 | | .82 |
| 1995 | | .93 |
| 1996 | | 1.02 |
| 1997 | | 1.11 |
| 1998 | | .97 |
| 1999 | | 1.57 |
| 2000 | | 1.04 |
| 2001 | | 1.19 |
| 2002 | | 1.57 |
| 2003 | | 2.01 |
| 2004 | | 2.59 |
| 2005 | | 2.83 |
| 2006 | | 4.43 |
| 2007 | | 5.15 |
| 2008 | | 5.58 |
| 2009 | | 4.67 |
| 2010 | | 6.82 |
|
|