|
| year | consumption | change |
| 1980 | | NA |
| 1981 | | NA |
| 1982 | | NA |
| 1983 | | NA |
| 1984 | | NA |
| 1985 | 3.29 | NA |
| 1986 | 2.49 | -24.24 % |
| 1987 | 2.90 | 16.43 % |
| 1988 | 1.57 | -45.90 % |
| 1989 | 3.23 | 105.73 % |
| 1990 | 3.21 | -0.63 % |
| 1991 | 3.32 | 3.44 % |
| 1992 | 3.37 | 1.58 % |
| 1993 | 3.49 | 3.44 % |
| 1994 | 3.55 | 1.96 % |
| 1995 | 3.55 | -0.06 % |
| 1996 | 3.63 | 2.04 % |
| 1997 | 3.70 | 1.97 % |
| 1998 | 3.74 | 1.22 % |
| 1999 | 3.74 | 0.00 % |
| 2000 | 3.84 | 2.65 % |
| 2001 | 3.85 | 0.27 % |
| 2002 | 4.20 | 9.10 % |
| 2003 | 4.24 | 0.94 % |
| 2004 | 4.37 | 3.03 % |
| 2005 | 4.86 | 11.22 % |
| 2006 | 4.40 | -9.41 % |
| 2007 | 4.51 | 2.38 % |
| 2008 | 4.57 | 1.34 % |
| 2009 | 4.70 | 2.86 % |
| 2010 | 4.70 | 0.00 % |
| 2011 | | NA |
|
|