|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 5.47 | 6.80 |
| 1987 | 2.20 | 3.95 |
| 1988 | 2.57 | 1.98 |
| 1989 | 2.13 | 1.84 |
| 1990 | 2.24 | 1.96 |
| 1991 | 2.88 | 1.80 |
| 1992 | 2.16 | 1.78 |
| 1993 | 2.76 | 2.06 |
| 1994 | 2.76 | |
| 1995 | 2.76 | 4.18 |
| 1996 | 2.75 | 4.17 |
| 1997 | 2.64 | 1.99 |
| 1998 | 2.87 | 1.89 |
| 1999 | 2.99 | 1.85 |
| 2000 | 3.38 | 2.28 |
| 2001 | 2.59 | 1.89 |
| 2002 | 3.27 | 2.90 |
| 2003 | 3.53 | 2.45 |
| 2004 | 3.45 | 2.47 |
| 2005 | 3.30 | 2.24 |
| 2006 | 1.40 | 2.48 |
| 2007 | 1.80 | 2.22 |
| 2008 | 1.59 | .93 |
| 2009 | 1.94 | 2.76 |
| 2010 | 2.01 | 2.66 |
|
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