|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 2.27 | 2.57 |
| 1987 | 2.60 | 2.60 |
| 1988 | 2.35 | 2.35 |
| 1989 | .80 | .80 |
| 1990 | .81 | .81 |
| 1991 | 2.82 | .57 |
| 1992 | 3.59 | 5.22 |
| 1993 | 3.90 | 3.90 |
| 1994 | 4.41 | 5.78 |
| 1995 | 4.71 | 6.19 |
| 1996 | 4.61 | 6.19 |
| 1997 | 4.36 | 5.74 |
| 1998 | 4.60 | 6.01 |
| 1999 | 5.15 | 7.33 |
| 2000 | 6.97 | 9.31 |
| 2001 | 4.32 | 7.22 |
| 2002 | 4.51 | 5.78 |
| 2003 | 4.02 | 6.63 |
| 2004 | 3.97 | 7.27 |
| 2005 | 4.17 | 7.20 |
| 2006 | 4.38 | 7.12 |
| 2007 | 3.35 | 6.90 |
| 2008 | 3.39 | 6.99 |
| 2009 | 3.52 | 6.90 |
| 2010 | 3.88 | 7.07 |
|
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