|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 2.17 | 1.54 |
| 1987 | 1.62 | 1.24 |
| 1988 | 1.31 | 1.61 |
| 1989 | 2.18 | 1.76 |
| 1990 | 2.22 | 1.64 |
| 1991 | 2.25 | 1.74 |
| 1992 | 4.15 | 1.84 |
| 1993 | 1.79 | 1.43 |
| 1994 | 1.79 | 1.38 |
| 1995 | 1.98 | 1.92 |
| 1996 | 1.55 | 1.14 |
| 1997 | 1.45 | 1.84 |
| 1998 | 2.78 | 1.89 |
| 1999 | 3.51 | 3.35 |
| 2000 | 3.79 | 2.01 |
| 2001 | 2.56 | 2.91 |
| 2002 | 3.28 | 2.11 |
| 2003 | 3.44 | 1.82 |
| 2004 | 2.56 | 1.90 |
| 2005 | 3.36 | 2.05 |
| 2006 | 24.75 | 5.27 |
| 2007 | 3.46 | 6.32 |
| 2008 | 4.16 | 1.94 |
| 2009 | 3.68 | 1.99 |
| 2010 | 2.72 | 1.83 |
|
|
