|
| year | consumption | change |
| 1980 | .67 | NA |
| 1981 | .72 | 7.46 % |
| 1982 | .78 | 8.33 % |
| 1983 | .78 | 0.00 % |
| 1984 | | NA |
| 1985 | .80 | NA |
| 1986 | .80 | 0.10 % |
| 1987 | .80 | 0.00 % |
| 1988 | .80 | -0.27 % |
| 1989 | .85 | 5.66 % |
| 1990 | .89 | 4.92 % |
| 1991 | .89 | 0.00 % |
| 1992 | .91 | 2.02 % |
| 1993 | .91 | 0.27 % |
| 1994 | .87 | -4.50 % |
| 1995 | .93 | 7.41 % |
| 1996 | .93 | -0.27 % |
| 1997 | .93 | 0.27 % |
| 1998 | .93 | 0.00 % |
| 1999 | .93 | 0.00 % |
| 2000 | .97 | 4.19 % |
| 2001 | .97 | 0.27 % |
| 2002 | 1.02 | 4.50 % |
| 2003 | 1.02 | 0.00 % |
| 2004 | 1.06 | 4.31 % |
| 2005 | 1.13 | 6.40 % |
| 2006 | 1.10 | -2.07 % |
| 2007 | 1.13 | 1.85 % |
| 2008 | 1.13 | 0.00 % |
| 2009 | 1.15 | 2.08 % |
| 2010 | 1.15 | 0.00 % |
| 2011 | | NA |
|
|