|
| year | production | consumption |
| 1980 | 33.73 | 57.73 |
| 1981 | 34.35 | 56.02 |
| 1982 | 35.77 | 55.57 |
| 1983 | 37.81 | 55.89 |
| 1984 | 37.96 | 57.22 |
| 1985 | 40.42 | 59.08 |
| 1986 | 41.51 | 60.22 |
| 1987 | 41.98 | 61.63 |
| 1988 | 42.12 | 62.08 |
| 1989 | 41.34 | 62.91 |
| 1990 | 40.17 | 61.95 |
| 1991 | 44.88 | 73.35 |
| 1992 | 97.45 | 118.24 |
| 1993 | 95.74 | 115.99 |
| 1994 | 94.01 | 113.17 |
| 1995 | 94.15 | 113.58 |
| 1996 | 95.12 | 113.76 |
| 1997 | 93.64 | 111.99 |
| 1998 | 92.97 | 112.29 |
| 1999 | 95.02 | 113.11 |
| 2000 | 95.73 | 115.37 |
| 2001 | 97.35 | 115.88 |
| 2002 | 98.67 | 116.87 |
| 2003 | 101.14 | 119.77 |
| 2004 | 103.82 | 122.32 |
| 2005 | 103.31 | 122.19 |
| 2006 | 103.05 | 122.06 |
| 2007 | 102.50 | 123.92 |
| 2008 | 102.68 | 123.69 |
| 2009 | 98.69 | 115.40 |
| 2010 | 102.07 | 120.33 |
|
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