|
| year | production | consumption |
| 1984 | .51 | 4.60 |
| 1985 | .51 | 4.64 |
| 1986 | .83 | 4.11 |
| 1987 | .70 | 4.39 |
| 1988 | 1.05 | 4.25 |
| 1989 | .98 | 4.55 |
| 1990 | .93 | 4.26 |
| 1991 | .92 | 4.32 |
| 1992 | 1.14 | 4.21 |
| 1993 | .89 | 4.29 |
| 1994 | .99 | 4.42 |
| 1995 | 1.14 | 4.29 |
| 1996 | 1.23 | 4.06 |
| 1997 | 1.42 | 4.04 |
| 1998 | 1.42 | 4.19 |
| 1999 | 1.20 | 4.32 |
| 2000 | 1.49 | 4.50 |
| 2001 | 1.90 | 4.64 |
| 2002 | 1.94 | 4.39 |
| 2003 | 1.84 | 4.32 |
| 2004 | 1.68 | 4.48 |
| 2005 | 1.84 | 4.75 |
| 2006 | 1.62 | 5.47 |
| 2007 | 1.08 | 4.51 |
| 2008 | 1.05 | 4.73 |
| 2009 | 1.08 | 3.31 |
| 2010 | 1.78 | 2.58 |
|
|
