|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | | 1.30 |
| 1987 | | .08 |
| 1988 | | .60 |
| 1989 | | .57 |
| 1990 | | .70 |
| 1991 | | .88 |
| 1992 | | 1.18 |
| 1993 | | .85 |
| 1994 | | 1.25 |
| 1995 | | 1.23 |
| 1996 | | 1.22 |
| 1997 | | 1.27 |
| 1998 | | 1.27 |
| 1999 | | 1.72 |
| 2000 | | 2.91 |
| 2001 | | 2.04 |
| 2002 | | 2.45 |
| 2003 | | 4.01 |
| 2004 | | 4.28 |
| 2005 | | 3.80 |
| 2006 | | 4.37 |
| 2007 | | 4.39 |
| 2008 | | 2.13 |
| 2009 | | 2.11 |
| 2010 | | 2.45 |
|
|