|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | 1.42 |
| 1987 | | 1.76 |
| 1988 | | 2.24 |
| 1989 | | 2.50 |
| 1990 | | 2.74 |
| 1991 | | 3.19 |
| 1992 | | 3.97 |
| 1993 | | 3.90 |
| 1994 | | 3.90 |
| 1995 | | 3.90 |
| 1996 | | 3.90 |
| 1997 | | 4.71 |
| 1998 | | 5.23 |
| 1999 | | 5.23 |
| 2000 | | 7.97 |
| 2001 | | 5.01 |
| 2002 | | 5.01 |
| 2003 | | 5.14 |
| 2004 | | 6.67 |
| 2005 | | 7.03 |
| 2006 | | 7.34 |
| 2007 | | 7.55 |
| 2008 | | 8.48 |
| 2009 | | 8.18 |
| 2010 | | 8.65 |
|
|