|
| year | production | change |
| 1980 | .02 | NA |
| 1981 | .03 | 12.76 % |
| 1982 | .03 | -3.91 % |
| 1983 | .07 | 195.73 % |
| 1984 | .07 | -1.91 % |
| 1985 | .07 | -9.17 % |
| 1986 | .08 | 13.05 % |
| 1987 | .07 | -0.69 % |
| 1988 | .06 | -26.03 % |
| 1989 | .04 | -27.27 % |
| 1990 | .07 | 80.69 % |
| 1991 | .06 | -12.42 % |
| 1992 | .08 | 28.30 % |
| 1993 | .08 | -8.18 % |
| 1994 | .08 | 2.34 % |
| 1995 | .06 | -21.64 % |
| 1996 | .06 | -1.25 % |
| 1997 | .07 | 10.80 % |
| 1998 | .09 | 40.90 % |
| 1999 | .06 | -39.51 % |
| 2000 | .07 | 27.44 % |
| 2001 | .09 | 31.97 % |
| 2002 | .10 | 2.12 % |
| 2003 | .09 | -9.92 % |
| 2004 | .05 | -44.99 % |
| 2005 | .07 | 39.28 % |
| 2006 | .04 | -46.20 % |
| 2007 | .08 | 124.27 % |
| 2008 | .05 | -34.95 % |
| 2009 | .06 | 12.88 % |
| 2010 | .09 | 57.69 % |
|
|