|
| year | consumption | change |
| 1980 | | NA |
| 1981 | | NA |
| 1982 | | NA |
| 1983 | | NA |
| 1984 | | NA |
| 1985 | | NA |
| 1986 | | NA |
| 1987 | | NA |
| 1988 | | NA |
| 1989 | | NA |
| 1990 | | NA |
| 1991 | | NA |
| 1992 | .29 | NA |
| 1993 | .25 | -12.32 % |
| 1994 | .25 | -0.58 % |
| 1995 | .21 | -17.51 % |
| 1996 | .23 | 10.18 % |
| 1997 | .22 | -4.73 % |
| 1998 | .23 | 3.45 % |
| 1999 | .24 | 6.78 % |
| 2000 | .24 | -1.10 % |
| 2001 | .25 | 3.33 % |
| 2002 | .25 | 2.01 % |
| 2003 | .27 | 7.35 % |
| 2004 | .27 | 1.35 % |
| 2005 | .28 | 3.67 % |
| 2006 | .28 | -1.41 % |
| 2007 | .27 | -2.79 % |
| 2008 | .26 | -5.81 % |
| 2009 | .19 | -27.20 % |
| 2010 | .19 | 1.98 % |
|
|