|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 2.56 | 4.60 |
| 1987 | 2.45 | 4.50 |
| 1988 | 2.51 | 4.55 |
| 1989 | 2.45 | 4.50 |
| 1990 | 2.41 | 4.36 |
| 1991 | 3.93 | 4.16 |
| 1992 | 4.28 | 4.67 |
| 1993 | 4.07 | 4.65 |
| 1994 | 3.17 | 5.29 |
| 1995 | 4.25 | 6.20 |
| 1996 | 3.44 | 5.96 |
| 1997 | 4.17 | 7.59 |
| 1998 | 4.58 | 8.47 |
| 1999 | 4.19 | 8.24 |
| 2000 | 4.40 | 7.81 |
| 2001 | 4.89 | 7.86 |
| 2002 | 4.07 | 7.24 |
| 2003 | 3.95 | 6.79 |
| 2004 | 4.26 | 8.10 |
| 2005 | 4.27 | 8.65 |
| 2006 | 4.18 | 8.39 |
| 2007 | 4.05 | 9.54 |
| 2008 | 3.82 | 8.44 |
| 2009 | 4.54 | 8.53 |
| 2010 | 4.36 | 7.99 |
|
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