|
| year | consumption | change |
| 1980 | | NA |
| 1981 | | NA |
| 1982 | | NA |
| 1983 | | NA |
| 1984 | | NA |
| 1985 | | NA |
| 1986 | | NA |
| 1987 | | NA |
| 1988 | | NA |
| 1989 | | NA |
| 1990 | | NA |
| 1991 | | NA |
| 1992 | 32.00 | NA |
| 1993 | 34.00 | 6.25 % |
| 1994 | 32.00 | -5.88 % |
| 1995 | 25.00 | -21.88 % |
| 1996 | 27.00 | 8.00 % |
| 1997 | 27.00 | 0.00 % |
| 1998 | 27.00 | 0.00 % |
| 1999 | 25.00 | -7.41 % |
| 2000 | 21.32 | -14.71 % |
| 2001 | 24.16 | 13.30 % |
| 2002 | 25.03 | 3.62 % |
| 2003 | 24.09 | -3.75 % |
| 2004 | 25.01 | 3.82 % |
| 2005 | 25.22 | 0.82 % |
| 2006 | 27.06 | 7.31 % |
| 2007 | 28.51 | 5.36 % |
| 2008 | 27.41 | -3.88 % |
| 2009 | 24.63 | -10.14 % |
| 2010 | 25.55 | 3.75 % |
| 2011 | 26.14 | 2.30 % |
|
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