|
| year | production | consumption |
| 1984 | | |
| 1985 | | |
| 1986 | 1.86 | 2.41 |
| 1987 | 1.94 | 2.43 |
| 1988 | 1.98 | 1.86 |
| 1989 | 2.07 | 2.54 |
| 1990 | 2.11 | 2.58 |
| 1991 | 2.13 | 2.66 |
| 1992 | 1.33 | 1.92 |
| 1993 | 1.02 | 1.53 |
| 1994 | .88 | 1.41 |
| 1995 | 1.39 | 1.96 |
| 1996 | 1.39 | 1.96 |
| 1997 | 1.43 | 2.00 |
| 1998 | 1.43 | 2.00 |
| 1999 | 1.43 | 2.00 |
| 2000 | 1.47 | 2.08 |
| 2001 | | 2.17 |
| 2002 | 1.51 | 2.19 |
| 2003 | 1.51 | 2.21 |
| 2004 | 1.22 | 2.55 |
| 2005 | 2.15 | 2.70 |
| 2006 | 1.23 | 2.37 |
| 2007 | .92 | 3.27 |
| 2008 | 1.23 | 4.29 |
| 2009 | | 3.23 |
| 2010 | | 3.23 |
|
|