|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 3.07 | 2.57 |
| 1987 | 3.27 | 2.73 |
| 1988 | 3.11 | 2.58 |
| 1989 | 3.26 | 3.26 |
| 1990 | 2.80 | 2.80 |
| 1991 | 1.46 | 2.46 |
| 1992 | 3.60 | 2.72 |
| 1993 | 2.73 | 2.09 |
| 1994 | 2.67 | 2.26 |
| 1995 | 2.91 | 2.47 |
| 1996 | 4.53 | 4.53 |
| 1997 | 2.84 | 2.87 |
| 1998 | 2.54 | 2.51 |
| 1999 | 3.57 | 3.57 |
| 2000 | 3.27 | 7.04 |
| 2001 | 3.99 | 9.42 |
| 2002 | 3.25 | 10.65 |
| 2003 | 2.86 | 11.40 |
| 2004 | 3.43 | 10.66 |
| 2005 | 3.46 | 10.70 |
| 2006 | 4.24 | 12.92 |
| 2007 | 4.32 | 12.04 |
| 2008 | 5.12 | 11.92 |
| 2009 | 5.11 | 12.90 |
| 2010 | 3.99 | 12.28 |
|
|
