|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | .15 | 1.78 |
| 1987 | .41 | 1.96 |
| 1988 | .30 | 1.90 |
| 1989 | .20 | 1.89 |
| 1990 | .27 | 2.07 |
| 1991 | .28 | 2.15 |
| 1992 | .37 | 2.24 |
| 1993 | .30 | 2.33 |
| 1994 | .22 | 2.35 |
| 1995 | .13 | 1.74 |
| 1996 | .65 | 2.22 |
| 1997 | .54 | 2.95 |
| 1998 | .89 | 3.08 |
| 1999 | 1.02 | 3.21 |
| 2000 | 1.01 | 3.29 |
| 2001 | 1.12 | 3.28 |
| 2002 | 1.30 | 3.17 |
| 2003 | | 4.07 |
| 2004 | | 6.21 |
| 2005 | | 3.69 |
| 2006 | .00 | 3.68 |
| 2007 | | 4.13 |
| 2008 | | 4.29 |
| 2009 | | 4.89 |
| 2010 | | 8.36 |
|
|
