|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 2.73 | 3.04 |
| 1987 | 2.99 | 3.28 |
| 1988 | 3.36 | 3.68 |
| 1989 | 3.28 | 3.74 |
| 1990 | 2.85 | 3.60 |
| 1991 | 2.84 | 3.76 |
| 1992 | 2.38 | 4.01 |
| 1993 | 2.20 | 4.07 |
| 1994 | 2.85 | 4.21 |
| 1995 | 2.38 | 4.16 |
| 1996 | 2.21 | 4.08 |
| 1997 | 3.30 | 4.23 |
| 1998 | 3.32 | 4.46 |
| 1999 | 3.46 | 4.72 |
| 2000 | 3.57 | 4.94 |
| 2001 | 3.51 | 5.49 |
| 2002 | 3.58 | 5.33 |
| 2003 | 3.40 | 6.59 |
| 2004 | .92 | 6.57 |
| 2005 | | 7.83 |
| 2006 | | 7.48 |
| 2007 | | 8.06 |
| 2008 | | 8.90 |
| 2009 | | 8.83 |
| 2010 | | 9.18 |
|
|