|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | 2.04 |
| 1987 | | 1.43 |
| 1988 | | 1.43 |
| 1989 | | 1.02 |
| 1990 | | .92 |
| 1991 | | .86 |
| 1992 | | 2.24 |
| 1993 | | 1.94 |
| 1994 | | 1.98 |
| 1995 | | 2.43 |
| 1996 | | 2.48 |
| 1997 | | 2.64 |
| 1998 | | 4.27 |
| 1999 | | 5.27 |
| 2000 | | 5.33 |
| 2001 | | 5.38 |
| 2002 | | 5.50 |
| 2003 | | 5.38 |
| 2004 | | 5.20 |
| 2005 | | 5.50 |
| 2006 | | 5.41 |
| 2007 | | 5.40 |
| 2008 | | 5.46 |
| 2009 | | 4.69 |
| 2010 | | 4.75 |
|
|