|
| year | consumption | change |
| 1980 | .21 | NA |
| 1981 | .31 | 47.62 % |
| 1982 | .29 | -6.45 % |
| 1983 | .31 | 6.90 % |
| 1984 | .31 | 0.00 % |
| 1985 | .32 | 4.26 % |
| 1986 | .32 | -0.09 % |
| 1987 | .47 | 46.92 % |
| 1988 | .56 | 18.59 % |
| 1989 | .61 | 7.77 % |
| 1990 | .61 | 0.00 % |
| 1991 | .70 | 14.63 % |
| 1992 | .70 | 0.03 % |
| 1993 | .72 | 3.63 % |
| 1994 | .82 | 13.16 % |
| 1995 | .82 | 0.09 % |
| 1996 | .90 | 10.44 % |
| 1997 | .93 | 2.71 % |
| 1998 | .90 | -3.08 % |
| 1999 | .90 | 0.00 % |
| 2000 | .92 | 2.33 % |
| 2001 | .88 | -4.33 % |
| 2002 | .78 | -11.22 % |
| 2003 | .78 | 0.00 % |
| 2004 | .84 | 8.04 % |
| 2005 | 1.03 | 22.86 % |
| 2006 | 1.17 | 13.37 % |
| 2007 | 1.20 | 2.47 % |
| 2008 | 1.20 | 0.00 % |
| 2009 | 1.20 | 0.00 % |
| 2010 | 1.20 | 0.00 % |
| 2011 | | NA |
|
|