|
| year | production | change |
| 1980 | .09 | NA |
| 1981 | .08 | -5.47 % |
| 1982 | .09 | 14.29 % |
| 1983 | .10 | 4.12 % |
| 1984 | .11 | 9.76 % |
| 1985 | .11 | 0.52 % |
| 1986 | .11 | -1.92 % |
| 1987 | .09 | -13.07 % |
| 1988 | .08 | -13.61 % |
| 1989 | .09 | 11.20 % |
| 1990 | .08 | -4.98 % |
| 1991 | .09 | 2.64 % |
| 1992 | .09 | 0.11 % |
| 1993 | .09 | 5.02 % |
| 1994 | .10 | 12.37 % |
| 1995 | .10 | -0.88 % |
| 1996 | .10 | -4.79 % |
| 1997 | .09 | -1.23 % |
| 1998 | .10 | 6.68 % |
| 1999 | .09 | -11.10 % |
| 2000 | .17 | 86.31 % |
| 2001 | .28 | 66.22 % |
| 2002 | .38 | 37.37 % |
| 2003 | .43 | 14.23 % |
| 2004 | .46 | 5.57 % |
| 2005 | .57 | 24.58 % |
| 2006 | .57 | -0.34 % |
| 2007 | .60 | 6.05 % |
| 2008 | .56 | -6.52 % |
| 2009 | .54 | -5.21 % |
| 2010 | .56 | 4.61 % |
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