|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | |
| 1987 | | 1.32 |
| 1988 | | 1.42 |
| 1989 | | 1.72 |
| 1990 | | 1.78 |
| 1991 | | 2.06 |
| 1992 | | 2.06 |
| 1993 | | 1.29 |
| 1994 | | 2.13 |
| 1995 | | 2.17 |
| 1996 | | 2.16 |
| 1997 | | 2.17 |
| 1998 | | 2.19 |
| 1999 | | 2.19 |
| 2000 | | 2.18 |
| 2001 | | 2.25 |
| 2002 | | 2.29 |
| 2003 | | 2.29 |
| 2004 | | 2.85 |
| 2005 | | 2.88 |
| 2006 | | 2.76 |
| 2007 | | 2.66 |
| 2008 | | 4.03 |
| 2009 | | 2.90 |
| 2010 | | 2.90 |
|
|