|
| year | consumption | change |
| 1980 | .00 | NA |
| 1981 | .00 | 13.21 % |
| 1982 | .00 | -11.67 % |
| 1983 | .00 | 27.04 % |
| 1984 | .00 | 28.22 % |
| 1985 | .00 | 6.95 % |
| 1986 | .00 | 1.44 % |
| 1987 | .00 | 13.52 % |
| 1988 | .00 | 47.65 % |
| 1989 | .01 | 7.22 % |
| 1990 | .01 | 8.51 % |
| 1991 | .01 | 10.58 % |
| 1992 | .01 | -4.79 % |
| 1993 | .00 | -26.00 % |
| 1994 | .01 | 57.85 % |
| 1995 | .01 | -2.37 % |
| 1996 | .01 | 1.52 % |
| 1997 | .01 | 1.20 % |
| 1998 | .01 | -0.74 % |
| 1999 | .01 | -1.49 % |
| 2000 | .01 | -0.45 % |
| 2001 | .01 | 8.21 % |
| 2002 | .01 | 2.11 % |
| 2003 | .01 | 0.28 % |
| 2004 | .01 | -8.50 % |
| 2005 | .01 | -0.45 % |
| 2006 | .01 | -3.01 % |
| 2007 | .01 | -4.50 % |
| 2008 | .00 | -33.98 % |
| 2009 | .00 | 8.13 % |
| 2010 | .00 | 6.61 % |
|
|