|
| year | consumption | change |
| 1980 | .08 | NA |
| 1981 | .08 | -8.93 % |
| 1982 | .09 | 19.33 % |
| 1983 | .09 | 2.95 % |
| 1984 | .09 | 1.25 % |
| 1985 | .10 | 10.41 % |
| 1986 | .11 | 6.78 % |
| 1987 | .12 | 5.32 % |
| 1988 | .12 | 3.62 % |
| 1989 | .12 | -4.60 % |
| 1990 | .11 | -5.73 % |
| 1991 | .13 | 18.49 % |
| 1992 | .11 | -13.52 % |
| 1993 | .10 | -10.07 % |
| 1994 | .09 | -5.63 % |
| 1995 | .10 | 5.52 % |
| 1996 | .08 | -24.30 % |
| 1997 | .06 | -17.97 % |
| 1998 | .06 | 0.16 % |
| 1999 | .06 | -1.08 % |
| 2000 | .06 | 2.58 % |
| 2001 | .07 | 3.23 % |
| 2002 | .07 | 6.72 % |
| 2003 | .07 | -4.44 % |
| 2004 | .07 | 6.86 % |
| 2005 | .07 | 1.06 % |
| 2006 | .08 | 14.45 % |
| 2007 | .09 | 3.66 % |
| 2008 | .09 | 6.00 % |
| 2009 | .09 | -0.23 % |
| 2010 | .09 | 2.98 % |
|
|