|
| year | production | consumption |
| 1980 | 4.50 | 180.00 |
| 1981 | 4.24 | 166.00 |
| 1982 | | 180.00 |
| 1983 | 3.50 | 184.00 |
| 1984 | | 181.00 |
| 1985 | | 219.00 |
| 1986 | | 225.00 |
| 1987 | 4.40 | 223.35 |
| 1988 | .35 | 221.07 |
| 1989 | .35 | 222.83 |
| 1990 | .49 | 241.00 |
| 1991 | .32 | 200.00 |
| 1992 | .28 | 186.00 |
| 1993 | 2.47 | 171.98 |
| 1994 | 2.12 | 168.10 |
| 1995 | 1.77 | 208.36 |
| 1996 | 1.41 | 218.60 |
| 1997 | 1.41 | 181.52 |
| 1998 | 1.06 | 134.90 |
| 1999 | .71 | 119.01 |
| 2000 | 2.12 | 192.82 |
| 2001 | .14 | 204.97 |
| 2002 | .07 | 173.11 |
| 2003 | .07 | 190.77 |
| 2004 | .04 | 187.20 |
| 2005 | | 190.70 |
| 2006 | | 197.76 |
| 2007 | 10.59 | 118.31 |
| 2008 | 3.88 | 113.36 |
| 2009 | .35 | 73.10 |
| 2010 | 1.77 | 89.70 |
| 2011 | 14.48 | 107.71 |
|
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