|
| year | consumption | change |
| 1980 | 2.80 | NA |
| 1981 | 2.50 | -10.71 % |
| 1982 | 3.40 | 36.00 % |
| 1983 | | NA |
| 1984 | 2.23 | NA |
| 1985 | 2.23 | -0.16 % |
| 1986 | 2.23 | 0.11 % |
| 1987 | 2.72 | 21.89 % |
| 1988 | 2.80 | 2.80 % |
| 1989 | 2.81 | 0.27 % |
| 1990 | 2.93 | 4.57 % |
| 1991 | 2.89 | -1.38 % |
| 1992 | 2.89 | -0.27 % |
| 1993 | 3.04 | 5.37 % |
| 1994 | 3.19 | 4.86 % |
| 1995 | 3.27 | 2.72 % |
| 1996 | 3.27 | -0.27 % |
| 1997 | 3.40 | 4.18 % |
| 1998 | 3.40 | 0.00 % |
| 1999 | 3.40 | 0.00 % |
| 2000 | 3.50 | 2.85 % |
| 2001 | 3.51 | 0.31 % |
| 2002 | 3.53 | 0.55 % |
| 2003 | 3.74 | 5.99 % |
| 2004 | 4.04 | 7.95 % |
| 2005 | 4.40 | 8.94 % |
| 2006 | 4.47 | 1.65 % |
| 2007 | 4.31 | -3.63 % |
| 2008 | 3.26 | -24.35 % |
| 2009 | 4.56 | 39.89 % |
| 2010 | 4.55 | -0.21 % |
| 2011 | | NA |
|
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