|
| year | production | consumption |
| 1980 | | |
| 1981 | 1.94 | |
| 1982 | | |
| 1983 | | |
| 1984 | | |
| 1985 | | |
| 1986 | | |
| 1987 | 1.90 | 1.94 |
| 1988 | 2.83 | 2.83 |
| 1989 | 2.82 | 2.82 |
| 1990 | | |
| 1991 | 3.23 | 3.23 |
| 1992 | 3.53 | 3.53 |
| 1993 | 3.53 | 3.53 |
| 1994 | 3.53 | 3.53 |
| 1995 | 4.24 | 4.24 |
| 1996 | 4.24 | 4.24 |
| 1997 | 3.53 | 3.53 |
| 1998 | 3.53 | 3.53 |
| 1999 | 3.53 | 3.53 |
| 2000 | 4.94 | 4.94 |
| 2001 | 5.65 | 5.65 |
| 2002 | 3.53 | 3.53 |
| 2003 | 5.30 | 5.30 |
| 2004 | 6.00 | 6.00 |
| 2005 | 9.18 | 9.18 |
| 2006 | 9.89 | 9.89 |
| 2007 | 9.71 | 9.71 |
| 2008 | 9.18 | 9.18 |
| 2009 | 10.45 | 10.45 |
| 2010 | 11.65 | 11.65 |
| 2011 | 8.48 | 8.48 |
|
|
