|
| year | consumption | change |
| 1980 | .20 | NA |
| 1981 | .40 | 100.00 % |
| 1982 | .40 | 0.00 % |
| 1983 | .40 | 0.00 % |
| 1984 | .40 | 0.00 % |
| 1985 | .40 | 0.00 % |
| 1986 | .37 | -8.45 % |
| 1987 | .37 | 0.00 % |
| 1988 | .37 | -0.27 % |
| 1989 | .32 | -11.62 % |
| 1990 | .32 | 0.00 % |
| 1991 | .27 | -15.41 % |
| 1992 | .32 | 17.90 % |
| 1993 | .32 | 0.27 % |
| 1994 | .32 | 0.01 % |
| 1995 | .32 | -0.27 % |
| 1996 | .32 | 0.00 % |
| 1997 | .32 | 0.27 % |
| 1998 | .32 | 0.00 % |
| 1999 | .32 | 0.00 % |
| 2000 | .39 | 19.98 % |
| 2001 | .39 | 0.27 % |
| 2002 | .39 | 0.00 % |
| 2003 | .39 | 0.00 % |
| 2004 | .43 | 10.56 % |
| 2005 | .48 | 10.78 % |
| 2006 | .49 | 4.09 % |
| 2007 | .46 | -6.19 % |
| 2008 | .48 | 4.40 % |
| 2009 | .48 | 0.00 % |
| 2010 | .48 | 0.00 % |
| 2011 | | NA |
|
|