|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 6.01 | 2.37 |
| 1987 | 6.44 | 2.54 |
| 1988 | 5.80 | 2.62 |
| 1989 | 6.81 | 3.13 |
| 1990 | 6.54 | 4.44 |
| 1991 | 3.18 | 2.50 |
| 1992 | 4.73 | 5.73 |
| 1993 | 5.86 | 3.70 |
| 1994 | | 4.56 |
| 1995 | | 3.66 |
| 1996 | | |
| 1997 | | |
| 1998 | | 2.03 |
| 1999 | | 1.88 |
| 2000 | | 2.09 |
| 2001 | | 2.17 |
| 2002 | | 2.55 |
| 2003 | | 2.43 |
| 2004 | .00 | 2.84 |
| 2005 | | 3.56 |
| 2006 | | 2.90 |
| 2007 | | 2.45 |
| 2008 | | 2.72 |
| 2009 | | 2.96 |
| 2010 | | 2.39 |
|
|