|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 2.33 | 2.33 |
| 1987 | 2.90 | 2.90 |
| 1988 | | |
| 1989 | 2.37 | 2.37 |
| 1990 | 1.83 | 1.83 |
| 1991 | 2.54 | 2.54 |
| 1992 | 2.18 | 2.26 |
| 1993 | 2.65 | 1.91 |
| 1994 | 2.67 | 2.77 |
| 1995 | 2.69 | 2.80 |
| 1996 | 3.50 | 4.26 |
| 1997 | 2.14 | 2.24 |
| 1998 | 2.18 | 2.22 |
| 1999 | 2.18 | 2.96 |
| 2000 | 1.10 | 1.73 |
| 2001 | 2.08 | 2.08 |
| 2002 | 1.29 | 2.33 |
| 2003 | 1.42 | 2.46 |
| 2004 | 2.34 | 3.38 |
| 2005 | 1.80 | 3.32 |
| 2006 | 1.38 | 2.41 |
| 2007 | 2.58 | 4.00 |
| 2008 | 3.58 | 6.46 |
| 2009 | 1.19 | 1.31 |
| 2010 | 1.50 | 1.50 |
|
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