|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | .72 |
| 1987 | | .74 |
| 1988 | | .74 |
| 1989 | | .74 |
| 1990 | | .74 |
| 1991 | | .76 |
| 1992 | | .78 |
| 1993 | | .78 |
| 1994 | | .80 |
| 1995 | | 3.78 |
| 1996 | | 4.54 |
| 1997 | | 7.09 |
| 1998 | | 7.91 |
| 1999 | | 7.17 |
| 2000 | | 7.73 |
| 2001 | | 9.46 |
| 2002 | | 10.06 |
| 2003 | | 10.85 |
| 2004 | | 11.85 |
| 2005 | | 12.47 |
| 2006 | | 11.61 |
| 2007 | | 12.53 |
| 2008 | | 12.81 |
| 2009 | | 11.51 |
| 2010 | | 11.65 |
|
|