|
| year | consumption | change |
| 1980 | .16 | NA |
| 1981 | .19 | 18.75 % |
| 1982 | .19 | 0.00 % |
| 1983 | .19 | 0.00 % |
| 1984 | .14 | -26.32 % |
| 1985 | .14 | 0.00 % |
| 1986 | .13 | -9.39 % |
| 1987 | .15 | 16.11 % |
| 1988 | .15 | -0.27 % |
| 1989 | .15 | 0.27 % |
| 1990 | .15 | 0.00 % |
| 1991 | .18 | 20.17 % |
| 1992 | .15 | -17.01 % |
| 1993 | .15 | 0.26 % |
| 1994 | .15 | 0.01 % |
| 1995 | .15 | 0.00 % |
| 1996 | .15 | -0.27 % |
| 1997 | .15 | 0.27 % |
| 1998 | .15 | 0.00 % |
| 1999 | .15 | 0.00 % |
| 2000 | .17 | 13.57 % |
| 2001 | .17 | 0.28 % |
| 2002 | .22 | 29.35 % |
| 2003 | .22 | 0.00 % |
| 2004 | .22 | -0.27 % |
| 2005 | .26 | 19.76 % |
| 2006 | .26 | 0.64 % |
| 2007 | .28 | 8.96 % |
| 2008 | .26 | -8.22 % |
| 2009 | .42 | 61.20 % |
| 2010 | .42 | -0.03 % |
| 2011 | | NA |
|
|