|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 1.19 | 4.11 |
| 1987 | .95 | 3.04 |
| 1988 | 1.09 | 3.83 |
| 1989 | 1.68 | 4.37 |
| 1990 | 1.37 | 4.06 |
| 1991 | .93 | 4.86 |
| 1992 | .98 | 4.99 |
| 1993 | 1.05 | 5.14 |
| 1994 | 1.12 | 5.28 |
| 1995 | 1.29 | 4.53 |
| 1996 | 1.28 | 4.59 |
| 1997 | 1.26 | 5.49 |
| 1998 | 1.19 | 5.19 |
| 1999 | .21 | 3.65 |
| 2000 | .21 | 3.71 |
| 2001 | .21 | 2.59 |
| 2002 | | 2.38 |
| 2003 | | 2.41 |
| 2004 | | 2.42 |
| 2005 | | 2.64 |
| 2006 | | 2.41 |
| 2007 | | 3.81 |
| 2008 | | 4.49 |
| 2009 | | 4.63 |
| 2010 | | 4.79 |
|
|