|
| year | consumption | change |
| 1980 | 9.90 | NA |
| 1981 | 9.10 | -8.08 % |
| 1982 | | NA |
| 1983 | 9.50 | NA |
| 1984 | 10.40 | 9.47 % |
| 1985 | 10.56 | 1.54 % |
| 1986 | 10.84 | 2.65 % |
| 1987 | 13.75 | 26.85 % |
| 1988 | 12.96 | -5.78 % |
| 1989 | 16.55 | 27.71 % |
| 1990 | 15.85 | -4.22 % |
| 1991 | 14.70 | -7.23 % |
| 1992 | 16.51 | 12.30 % |
| 1993 | 17.68 | 7.06 % |
| 1994 | 20.49 | 15.93 % |
| 1995 | 22.78 | 11.14 % |
| 1996 | 19.19 | -15.75 % |
| 1997 | 20.88 | 8.82 % |
| 1998 | 23.89 | 14.41 % |
| 1999 | 26.94 | 12.78 % |
| 2000 | 25.10 | -6.85 % |
| 2001 | 24.06 | -4.13 % |
| 2002 | 25.05 | 4.13 % |
| 2003 | 26.02 | 3.87 % |
| 2004 | 26.09 | 0.27 % |
| 2005 | 25.81 | -1.09 % |
| 2006 | 25.98 | 0.67 % |
| 2007 | 26.33 | 1.34 % |
| 2008 | 28.11 | 6.75 % |
| 2009 | 28.88 | 2.76 % |
| 2010 | 31.22 | 8.10 % |
| 2011 | 28.00 | -10.32 % |
|
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