|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 51.80 | 51.71 |
| 1987 | 55.94 | 63.29 |
| 1988 | 53.30 | 62.05 |
| 1989 | 57.28 | 57.00 |
| 1990 | 105.05 | 93.38 |
| 1991 | 102.43 | 92.41 |
| 1992 | 100.84 | 83.24 |
| 1993 | 94.80 | 91.61 |
| 1994 | 98.60 | 92.16 |
| 1995 | 97.91 | 95.67 |
| 1996 | 94.81 | 90.58 |
| 1997 | 98.65 | 98.09 |
| 1998 | 97.30 | 100.11 |
| 1999 | 96.01 | 96.06 |
| 2000 | 28.26 | 29.25 |
| 2001 | 30.35 | 32.92 |
| 2002 | 27.16 | 32.25 |
| 2003 | 24.59 | 29.46 |
| 2004 | 15.28 | 16.07 |
| 2005 | 13.76 | 16.82 |
| 2006 | 7.88 | 9.18 |
| 2007 | 7.86 | 8.94 |
| 2008 | 7.34 | 8.55 |
| 2009 | 7.86 | 8.71 |
| 2010 | 9.17 | 9.93 |
|
|