|
| year | production | change |
| 1980 | .14 | NA |
| 1981 | .18 | 27.14 % |
| 1982 | .19 | 7.58 % |
| 1983 | .19 | -1.86 % |
| 1984 | .26 | 38.90 % |
| 1985 | .26 | -0.40 % |
| 1986 | .25 | -1.56 % |
| 1987 | .26 | 4.02 % |
| 1988 | .31 | 16.31 % |
| 1989 | .35 | 13.82 % |
| 1990 | .35 | 0.87 % |
| 1991 | .33 | -5.41 % |
| 1992 | .37 | 11.49 % |
| 1993 | .39 | 3.53 % |
| 1994 | .38 | -0.66 % |
| 1995 | .40 | 4.48 % |
| 1996 | .43 | 7.41 % |
| 1997 | .56 | 29.64 % |
| 1998 | .58 | 4.25 % |
| 1999 | .59 | 2.01 % |
| 2000 | .61 | 3.70 % |
| 2001 | .56 | -8.92 % |
| 2002 | .55 | -2.25 % |
| 2003 | .54 | -1.59 % |
| 2004 | .51 | -4.59 % |
| 2005 | .50 | -2.26 % |
| 2006 | .53 | 5.43 % |
| 2007 | .46 | -12.76 % |
| 2008 | .52 | 12.92 % |
| 2009 | .60 | 14.74 % |
| 2010 | .69 | 15.66 % |
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