|
| year | production | consumption |
| 1980 | | |
| 1981 | | |
| 1982 | | |
| 1983 | | |
| 1984 | | |
| 1985 | | 3.50 |
| 1986 | | 3.46 |
| 1987 | | 2.66 |
| 1988 | | 3.22 |
| 1989 | | 3.45 |
| 1990 | | 4.08 |
| 1991 | | 4.69 |
| 1992 | 5.59 | 5.24 |
| 1993 | 5.78 | 5.79 |
| 1994 | 5.93 | 6.10 |
| 1995 | | 6.68 |
| 1996 | | 7.18 |
| 1997 | 1.32 | 7.84 |
| 1998 | | 8.46 |
| 1999 | | 9.22 |
| 2000 | .69 | 11.37 |
| 2001 | .70 | 11.40 |
| 2002 | .80 | 12.13 |
| 2003 | .40 | 14.16 |
| 2004 | | 16.77 |
| 2005 | | 17.56 |
| 2006 | | 20.79 |
| 2007 | | 22.56 |
| 2008 | | 23.73 |
| 2009 | | 31.09 |
| 2010 | | 34.77 |
| 2011 | | 28.00 |
|
|