|
| year | production | consumption |
| 1980 | | 15.60 |
| 1981 | | 14.20 |
| 1982 | | 13.80 |
| 1983 | | 13.80 |
| 1984 | | 12.70 |
| 1985 | | 11.90 |
| 1986 | | 11.89 |
| 1987 | | 12.60 |
| 1988 | | 13.67 |
| 1989 | | 13.38 |
| 1990 | | 13.45 |
| 1991 | | 11.43 |
| 1992 | | 13.00 |
| 1993 | | 10.85 |
| 1994 | | 10.71 |
| 1995 | | 10.91 |
| 1996 | | 11.09 |
| 1997 | | 11.17 |
| 1998 | | 11.75 |
| 1999 | | 11.16 |
| 2000 | | 10.74 |
| 2001 | | 11.76 |
| 2002 | | 12.19 |
| 2003 | | 12.74 |
| 2004 | | 13.27 |
| 2005 | | 14.07 |
| 2006 | | 14.54 |
| 2007 | | 14.80 |
| 2008 | | 11.86 |
| 2009 | | 12.96 |
| 2010 | | 14.43 |
| 2011 | | 19.00 |
|
|