|
| year | production | change |
| 1980 | .13 | NA |
| 1981 | .12 | -4.63 % |
| 1982 | .11 | -6.60 % |
| 1983 | .13 | 14.80 % |
| 1984 | .12 | -7.00 % |
| 1985 | .12 | -2.99 % |
| 1986 | .14 | 22.19 % |
| 1987 | .16 | 10.34 % |
| 1988 | .16 | 4.86 % |
| 1989 | .16 | -3.09 % |
| 1990 | .17 | 8.65 % |
| 1991 | .19 | 9.00 % |
| 1992 | .18 | -4.72 % |
| 1993 | .16 | -10.42 % |
| 1994 | .15 | -7.25 % |
| 1995 | .14 | -3.46 % |
| 1996 | .14 | -1.96 % |
| 1997 | .13 | -8.33 % |
| 1998 | .13 | 1.34 % |
| 1999 | .15 | 17.85 % |
| 2000 | .15 | -4.40 % |
| 2001 | .14 | -3.62 % |
| 2002 | .14 | 2.06 % |
| 2003 | .15 | 3.28 % |
| 2004 | .15 | -2.12 % |
| 2005 | .16 | 5.81 % |
| 2006 | .13 | -13.13 % |
| 2007 | .13 | -0.04 % |
| 2008 | .11 | -20.51 % |
| 2009 | .11 | 5.27 % |
| 2010 | .12 | 8.36 % |
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