|
| year | production | consumption |
| 1980 | .10 | .10 |
| 1981 | .11 | .11 |
| 1982 | .22 | .22 |
| 1983 | .33 | .33 |
| 1984 | .44 | .44 |
| 1985 | 1.10 | 1.10 |
| 1986 | 2.20 | 2.20 |
| 1987 | 1.10 | 1.10 |
| 1988 | 1.10 | 1.10 |
| 1989 | 1.10 | 1.10 |
| 1990 | 1.10 | 1.10 |
| 1991 | 1.10 | 1.10 |
| 1992 | 1.10 | 1.10 |
| 1993 | 1.10 | 1.10 |
| 1994 | 1.10 | 1.10 |
| 1995 | 25.93 | 25.93 |
| 1996 | 55.92 | 55.92 |
| 1997 | 105.21 | 105.21 |
| 1998 | 270.75 | 175.40 |
| 1999 | 454.02 | 238.52 |
| 2000 | 454.25 | 261.79 |
| 2001 | 415.93 | 192.49 |
| 2002 | 551.22 | 298.46 |
| 2003 | 495.05 | 306.23 |
| 2004 | 660.12 | 434.15 |
| 2005 | 685.59 | 437.57 |
| 2006 | 713.97 | 468.16 |
| 2007 | 1,143.59 | 504.25 |
| 2008 | 850.42 | 516.11 |
| 2009 | 967.75 | 550.54 |
| 2010 | 954.71 | 537.51 |
| 2011 | 954.71 | 537.51 |
|
|
