|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 6.13 | 9.37 |
| 1987 | 4.73 | 8.37 |
| 1988 | 6.12 | 8.20 |
| 1989 | 6.34 | 6.84 |
| 1990 | 3.50 | 6.00 |
| 1991 | 2.72 | 11.45 |
| 1992 | 1.88 | 8.77 |
| 1993 | 1.74 | 10.79 |
| 1994 | | 16.25 |
| 1995 | | 19.70 |
| 1996 | | 18.14 |
| 1997 | | 28.12 |
| 1998 | | 29.12 |
| 1999 | | 35.73 |
| 2000 | | 36.00 |
| 2001 | | 31.62 |
| 2002 | | 34.03 |
| 2003 | | 37.38 |
| 2004 | | 35.63 |
| 2005 | | 31.48 |
| 2006 | | 32.62 |
| 2007 | | 29.74 |
| 2008 | | 36.85 |
| 2009 | | 53.04 |
| 2010 | | 46.03 |
|
|