|
| year | consumption | change |
| 1980 | .70 | NA |
| 1981 | .80 | 14.29 % |
| 1982 | .70 | -12.50 % |
| 1983 | .80 | 14.29 % |
| 1984 | | NA |
| 1985 | 1.04 | NA |
| 1986 | 1.01 | -3.55 % |
| 1987 | 1.05 | 4.03 % |
| 1988 | 1.73 | 64.76 % |
| 1989 | 1.91 | 10.45 % |
| 1990 | 2.09 | 9.35 % |
| 1991 | 2.33 | 11.53 % |
| 1992 | 2.21 | -4.80 % |
| 1993 | 2.46 | 11.32 % |
| 1994 | 2.60 | 5.33 % |
| 1995 | 2.53 | -2.42 % |
| 1996 | 2.56 | 1.25 % |
| 1997 | 2.59 | 1.18 % |
| 1998 | 2.64 | 1.63 % |
| 1999 | 2.64 | 0.00 % |
| 2000 | 2.64 | -0.02 % |
| 2001 | 2.80 | 6.12 % |
| 2002 | 2.83 | 1.15 % |
| 2003 | 2.94 | 4.03 % |
| 2004 | 2.69 | -8.73 % |
| 2005 | 2.63 | -1.93 % |
| 2006 | 2.56 | -2.98 % |
| 2007 | 2.35 | -7.89 % |
| 2008 | 1.32 | -43.85 % |
| 2009 | 1.46 | 10.41 % |
| 2010 | 1.46 | -0.26 % |
| 2011 | | NA |
|
|