|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 3.39 | 2.91 |
| 1987 | 3.39 | 4.09 |
| 1988 | 3.59 | 4.12 |
| 1989 | 3.49 | 4.63 |
| 1990 | 4.03 | 4.92 |
| 1991 | 5.07 | 4.57 |
| 1992 | 4.65 | 2.53 |
| 1993 | 5.08 | 2.75 |
| 1994 | 2.12 | 2.75 |
| 1995 | 5.29 | 5.51 |
| 1996 | 5.91 | 6.34 |
| 1997 | 2.41 | 2.84 |
| 1998 | 2.50 | 2.92 |
| 1999 | 2.16 | 2.16 |
| 2000 | 2.53 | 2.53 |
| 2001 | 2.56 | 2.56 |
| 2002 | 2.31 | 2.31 |
| 2003 | 2.27 | 2.27 |
| 2004 | 2.30 | 2.30 |
| 2005 | 2.31 | 2.31 |
| 2006 | 2.08 | 2.08 |
| 2007 | 2.05 | 2.05 |
| 2008 | 2.24 | 2.24 |
| 2009 | 2.67 | 2.67 |
| 2010 | 2.39 | 2.39 |
|
|