|
| year | consumption | change |
| 1980 | 12.00 | NA |
| 1981 | 12.00 | 0.00 % |
| 1982 | 12.00 | 0.00 % |
| 1983 | 12.00 | 0.00 % |
| 1984 | 13.60 | 13.33 % |
| 1985 | 14.35 | 5.54 % |
| 1986 | 14.49 | 0.94 % |
| 1987 | 16.07 | 10.95 % |
| 1988 | 15.01 | -6.65 % |
| 1989 | 15.38 | 2.50 % |
| 1990 | 15.60 | 1.45 % |
| 1991 | 15.47 | -0.86 % |
| 1992 | 15.36 | -0.71 % |
| 1993 | 15.34 | -0.12 % |
| 1994 | 15.00 | -2.24 % |
| 1995 | 15.18 | 1.25 % |
| 1996 | 15.14 | -0.27 % |
| 1997 | 15.45 | 2.03 % |
| 1998 | 14.83 | -4.02 % |
| 1999 | 14.83 | 0.00 % |
| 2000 | 14.94 | 0.75 % |
| 2001 | 14.98 | 0.27 % |
| 2002 | 22.04 | 47.08 % |
| 2003 | 25.18 | 14.25 % |
| 2004 | 25.02 | -0.63 % |
| 2005 | 25.08 | 0.25 % |
| 2006 | 26.53 | 5.78 % |
| 2007 | 26.44 | -0.34 % |
| 2008 | 19.74 | -25.33 % |
| 2009 | 19.73 | -0.07 % |
| 2010 | 19.90 | 0.89 % |
| 2011 | 45.00 | 126.09 % |
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