|
| year | consumption | change |
| 1980 | .70 | NA |
| 1981 | .76 | 8.57 % |
| 1982 | .76 | 0.00 % |
| 1983 | .74 | -2.63 % |
| 1984 | .76 | 2.70 % |
| 1985 | .79 | 3.58 % |
| 1986 | .79 | 0.07 % |
| 1987 | .81 | 3.23 % |
| 1988 | 1.86 | 128.94 % |
| 1989 | 1.89 | 1.37 % |
| 1990 | 1.94 | 2.58 % |
| 1991 | 2.05 | 5.98 % |
| 1992 | 2.10 | 2.26 % |
| 1993 | 2.00 | -4.83 % |
| 1994 | 2.17 | 8.79 % |
| 1995 | 2.35 | 8.38 % |
| 1996 | 2.36 | 0.44 % |
| 1997 | 2.37 | 0.27 % |
| 1998 | 2.41 | 1.78 % |
| 1999 | 2.41 | 0.00 % |
| 2000 | 2.39 | -1.12 % |
| 2001 | 2.41 | 1.13 % |
| 2002 | 2.41 | 0.00 % |
| 2003 | 2.50 | 3.62 % |
| 2004 | 2.70 | 7.89 % |
| 2005 | 2.82 | 4.46 % |
| 2006 | 3.19 | 13.24 % |
| 2007 | 3.70 | 15.94 % |
| 2008 | 4.49 | 21.38 % |
| 2009 | 3.73 | -16.94 % |
| 2010 | 3.75 | 0.63 % |
| 2011 | | NA |
|
|