|
| year | production | consumption |
| 1984 | 34.36 | 35.61 |
| 1985 | 31.59 | 31.76 |
| 1986 | 27.45 | 29.79 |
| 1987 | 30.58 | 31.50 |
| 1988 | 28.69 | 29.25 |
| 1989 | 27.98 | 25.58 |
| 1990 | 17.36 | 16.83 |
| 1991 | 18.64 | 10.42 |
| 1992 | 20.92 | 12.10 |
| 1993 | 11.94 | 12.61 |
| 1994 | 10.58 | 10.47 |
| 1995 | 6.86 | 7.69 |
| 1996 | 7.37 | 7.24 |
| 1997 | 3.47 | 3.64 |
| 1998 | 2.29 | 2.48 |
| 1999 | 1.15 | 1.05 |
| 2000 | 1.14 | 1.39 |
| 2001 | 1.46 | 1.81 |
| 2002 | 1.37 | 1.62 |
| 2003 | 1.42 | .66 |
| 2004 | 1.27 | .77 |
| 2005 | .90 | .79 |
| 2006 | .42 | .99 |
| 2007 | | .92 |
| 2008 | | .43 |
| 2009 | | .43 |
| 2010 | | .43 |
|
|