|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 12.55 | 23.92 |
| 1987 | 14.92 | 15.49 |
| 1988 | 14.87 | 15.25 |
| 1989 | 14.16 | 16.55 |
| 1990 | 15.23 | 17.35 |
| 1991 | 14.66 | 16.82 |
| 1992 | 15.36 | 17.40 |
| 1993 | 13.91 | 16.81 |
| 1994 | 16.97 | 20.13 |
| 1995 | 17.84 | 21.43 |
| 1996 | 17.40 | 23.03 |
| 1997 | 17.47 | 22.62 |
| 1998 | 18.98 | 23.33 |
| 1999 | 19.49 | 22.72 |
| 2000 | 18.26 | 23.50 |
| 2001 | 20.47 | 24.19 |
| 2002 | 22.33 | 26.59 |
| 2003 | 23.72 | 29.51 |
| 2004 | 24.92 | 36.32 |
| 2005 | 28.53 | 41.65 |
| 2006 | 28.32 | 37.83 |
| 2007 | 25.92 | 36.93 |
| 2008 | 25.74 | 31.31 |
| 2009 | 23.62 | 32.90 |
| 2010 | 18.49 | 31.69 |
|
|