|
| year | consumption | change |
| 1980 | .08 | NA |
| 1981 | .08 | 0.00 % |
| 1982 | .08 | 0.00 % |
| 1983 | .08 | 0.00 % |
| 1984 | .08 | 0.00 % |
| 1985 | .10 | 25.83 % |
| 1986 | .10 | 0.08 % |
| 1987 | .10 | 0.00 % |
| 1988 | .20 | 100.89 % |
| 1989 | .19 | -7.66 % |
| 1990 | .17 | -10.94 % |
| 1991 | .17 | 0.00 % |
| 1992 | .17 | -0.28 % |
| 1993 | .17 | 0.27 % |
| 1994 | .17 | 0.01 % |
| 1995 | .19 | 12.28 % |
| 1996 | .21 | 12.59 % |
| 1997 | .23 | 9.99 % |
| 1998 | .19 | -18.93 % |
| 1999 | .19 | 0.00 % |
| 2000 | .19 | -0.28 % |
| 2001 | .19 | 0.28 % |
| 2002 | .21 | 10.89 % |
| 2003 | .21 | 0.00 % |
| 2004 | .23 | 9.53 % |
| 2005 | .25 | 9.24 % |
| 2006 | .27 | 8.81 % |
| 2007 | .31 | 15.37 % |
| 2008 | .31 | 0.00 % |
| 2009 | .31 | 0.00 % |
| 2010 | .31 | 0.00 % |
| 2011 | | NA |
|
|