|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | 1.03 |
| 1987 | | 1.78 |
| 1988 | | 1.98 |
| 1989 | | 1.86 |
| 1990 | | .93 |
| 1991 | | .93 |
| 1992 | | 1.24 |
| 1993 | | .98 |
| 1994 | | .93 |
| 1995 | | 1.39 |
| 1996 | | 1.81 |
| 1997 | | 1.89 |
| 1998 | | 2.17 |
| 1999 | | 2.20 |
| 2000 | | 2.38 |
| 2001 | | 2.39 |
| 2002 | | 2.41 |
| 2003 | | 2.48 |
| 2004 | | 2.59 |
| 2005 | | 2.66 |
| 2006 | | 2.78 |
| 2007 | | 4.18 |
| 2008 | | 5.30 |
| 2009 | | 5.33 |
| 2010 | | 2.85 |
|
|