|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 4.66 | 4.50 |
| 1987 | 4.28 | 4.29 |
| 1988 | 3.57 | 5.64 |
| 1989 | 3.90 | 4.87 |
| 1990 | 4.07 | 4.49 |
| 1991 | 3.90 | 5.50 |
| 1992 | 3.95 | 4.77 |
| 1993 | 3.94 | 4.89 |
| 1994 | 4.02 | 5.19 |
| 1995 | 2.39 | 3.39 |
| 1996 | 2.05 | 3.15 |
| 1997 | 3.58 | 5.23 |
| 1998 | 3.58 | 5.70 |
| 1999 | 3.68 | 6.29 |
| 2000 | 3.63 | 7.58 |
| 2001 | 1.29 | 4.09 |
| 2002 | 1.36 | 4.09 |
| 2003 | .83 | 3.41 |
| 2004 | 1.22 | 3.40 |
| 2005 | 1.14 | 3.75 |
| 2006 | 1.14 | 3.75 |
| 2007 | .40 | .44 |
| 2008 | .42 | .42 |
| 2009 | .06 | .06 |
| 2010 | .08 | .04 |
|
|
