|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 2.96 | 5.07 |
| 1987 | 1.55 | 5.29 |
| 1988 | 3.48 | 5.71 |
| 1989 | 2.57 | 5.22 |
| 1990 | 2.47 | 4.75 |
| 1991 | 3.73 | 4.07 |
| 1992 | 2.21 | 4.33 |
| 1993 | 2.27 | 4.44 |
| 1994 | 2.38 | 4.50 |
| 1995 | 2.29 | 4.53 |
| 1996 | 2.35 | 4.59 |
| 1997 | 2.41 | 4.70 |
| 1998 | 2.45 | 4.74 |
| 1999 | 1.15 | 5.89 |
| 2000 | 14.40 | 6.41 |
| 2001 | 19.68 | 8.18 |
| 2002 | 20.68 | 9.11 |
| 2003 | 25.96 | 10.17 |
| 2004 | 28.62 | 11.30 |
| 2005 | 29.82 | 12.76 |
| 2006 | 40.01 | 15.82 |
| 2007 | 38.30 | 14.98 |
| 2008 | 26.06 | 14.89 |
| 2009 | 27.27 | 16.59 |
| 2010 | 34.84 | 26.31 |
|
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