|
| year | consumption | change |
| 1980 | 1.60 | NA |
| 1981 | 1.50 | -6.25 % |
| 1982 | 1.40 | -6.67 % |
| 1983 | 1.40 | 0.00 % |
| 1984 | 1.50 | 7.14 % |
| 1985 | 1.53 | 2.19 % |
| 1986 | 1.91 | 24.37 % |
| 1987 | 1.58 | -17.05 % |
| 1988 | 1.13 | -28.59 % |
| 1989 | 1.58 | 39.57 % |
| 1990 | 2.22 | 40.58 % |
| 1991 | 2.47 | 11.59 % |
| 1992 | 2.12 | -14.34 % |
| 1993 | 2.11 | -0.48 % |
| 1994 | 2.00 | -5.16 % |
| 1995 | 2.29 | 14.75 % |
| 1996 | 1.94 | -15.61 % |
| 1997 | 3.19 | 64.84 % |
| 1998 | 3.21 | 0.61 % |
| 1999 | 3.26 | 1.46 % |
| 2000 | 4.71 | 44.47 % |
| 2001 | 6.26 | 33.07 % |
| 2002 | 6.01 | -4.05 % |
| 2003 | 6.29 | 4.61 % |
| 2004 | 6.75 | 7.46 % |
| 2005 | 7.12 | 5.45 % |
| 2006 | 7.20 | 1.14 % |
| 2007 | 7.33 | 1.69 % |
| 2008 | 3.55 | -51.50 % |
| 2009 | 3.50 | -1.61 % |
| 2010 | 3.49 | -0.06 % |
| 2011 | | NA |
|
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