|
| year | production | consumption |
| 1980 | | |
| 1981 | | |
| 1982 | | |
| 1983 | | |
| 1984 | | |
| 1985 | | |
| 1986 | | |
| 1987 | | |
| 1988 | | |
| 1989 | | |
| 1990 | | |
| 1991 | | |
| 1992 | | 33.00 |
| 1993 | .05 | 40.00 |
| 1994 | .04 | 43.00 |
| 1995 | .04 | 48.00 |
| 1996 | .02 | 56.00 |
| 1997 | .03 | 55.00 |
| 1998 | .02 | 52.00 |
| 1999 | .02 | 52.00 |
| 2000 | .02 | 50.16 |
| 2001 | .01 | 52.09 |
| 2002 | .01 | 50.55 |
| 2003 | .01 | 51.26 |
| 2004 | .01 | 52.43 |
| 2005 | .01 | 53.68 |
| 2006 | .01 | 55.57 |
| 2007 | .01 | 55.08 |
| 2008 | .01 | 63.72 |
| 2009 | .01 | 55.39 |
| 2010 | .01 | 54.78 |
| 2011 | .01 | 55.15 |
|
|