|
| year | consumption | change |
| 1980 | 2.87 | NA |
| 1981 | 3.02 | 5.37 % |
| 1982 | 3.22 | 6.48 % |
| 1983 | 3.37 | 4.79 % |
| 1984 | 3.47 | 2.85 % |
| 1985 | 3.55 | 2.39 % |
| 1986 | 3.33 | -6.10 % |
| 1987 | 3.54 | 6.29 % |
| 1988 | 3.70 | 4.43 % |
| 1989 | 4.04 | 9.20 % |
| 1990 | 4.35 | 7.65 % |
| 1991 | 3.98 | -8.44 % |
| 1992 | 3.98 | -0.14 % |
| 1993 | 3.99 | 0.31 % |
| 1994 | 4.04 | 1.35 % |
| 1995 | 4.24 | 4.86 % |
| 1996 | 4.35 | 2.54 % |
| 1997 | 4.37 | 0.47 % |
| 1998 | 4.39 | 0.50 % |
| 1999 | 4.39 | 0.00 % |
| 2000 | 4.46 | 1.65 % |
| 2001 | 4.46 | -0.10 % |
| 2002 | 4.49 | 0.74 % |
| 2003 | 4.53 | 0.98 % |
| 2004 | 4.58 | 0.99 % |
| 2005 | 4.64 | 1.23 % |
| 2006 | 4.92 | 6.16 % |
| 2007 | 4.78 | -2.97 % |
| 2008 | 4.86 | 1.75 % |
| 2009 | 4.88 | 0.42 % |
| 2010 | 4.66 | -4.48 % |
| 2011 | | NA |
|
|