|
| year | production | consumption |
| 1980 | | 16.00 |
| 1981 | | 14.00 |
| 1982 | | 16.00 |
| 1983 | | 14.00 |
| 1984 | | 16.00 |
| 1985 | | 13.71 |
| 1986 | .30 | 15.90 |
| 1987 | | 18.12 |
| 1988 | | 21.30 |
| 1989 | | 23.66 |
| 1990 | | 20.00 |
| 1991 | | 20.13 |
| 1992 | 1.09 | 22.44 |
| 1993 | 1.60 | 23.43 |
| 1994 | 1.40 | 25.81 |
| 1995 | | 26.66 |
| 1996 | | 27.18 |
| 1997 | | 26.02 |
| 1998 | | 26.79 |
| 1999 | | 31.36 |
| 2000 | | 36.96 |
| 2001 | | 36.27 |
| 2002 | | 38.65 |
| 2003 | | 41.54 |
| 2004 | | 45.30 |
| 2005 | | 45.95 |
| 2006 | | 46.97 |
| 2007 | | 47.66 |
| 2008 | | 44.37 |
| 2009 | | 53.87 |
| 2010 | 7.19 | 64.73 |
| 2011 | 76.51 | 64.00 |
|
|