|
| year | consumption | change |
| 1980 | 7.90 | NA |
| 1981 | 9.20 | 16.46 % |
| 1982 | 9.10 | -1.09 % |
| 1983 | 8.90 | -2.20 % |
| 1984 | 9.20 | 3.37 % |
| 1985 | 9.08 | -1.35 % |
| 1986 | 9.63 | 6.10 % |
| 1987 | 7.18 | -25.42 % |
| 1988 | 7.27 | 1.19 % |
| 1989 | 7.40 | 1.78 % |
| 1990 | 6.75 | -8.70 % |
| 1991 | 4.03 | -40.31 % |
| 1992 | 3.74 | -7.31 % |
| 1993 | 3.86 | 3.35 % |
| 1994 | 3.86 | 0.00 % |
| 1995 | 3.86 | 0.00 % |
| 1996 | 3.86 | 0.00 % |
| 1997 | 3.86 | 0.00 % |
| 1998 | 3.86 | 0.00 % |
| 1999 | 3.86 | 0.00 % |
| 2000 | 4.80 | 24.31 % |
| 2001 | 4.80 | 0.00 % |
| 2002 | 4.80 | 0.00 % |
| 2003 | 4.80 | 0.00 % |
| 2004 | 4.80 | 0.00 % |
| 2005 | 4.86 | 1.20 % |
| 2006 | 5.11 | 5.19 % |
| 2007 | 5.76 | 12.74 % |
| 2008 | 5.46 | -5.19 % |
| 2009 | 5.40 | -1.14 % |
| 2010 | 5.40 | 0.00 % |
| 2011 | | NA |
|
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