What is the least illuminated phase for the planet Mars as seen from the Earth?

I looked at several years worth of Mars ephimerides and here's what I got: 

Date         Magnitude         Distance        Phase          Size
8/27/95        +0.9              11.4          .894            6.6"
11/4/94        +0.7              10.9          .891            7.0
4/15/93        +0.8              11.2          .899            6.9
9/23/92        +0.4               9.9          .869            7.8
3/9/91         +0.7              10.9          .896            7.2
8/1/90         -0.0               8.5          .842            9.1
1/10/89        +0.1               8.8          .880            8.8
6/12/88        -0.4               6.9          .850           11.1
11/2/86        -0.4               7.2          .852           10.7
9/17/84        +0.1               9.1          .850            8.5
Where the distance is given in light minutes, and the size of the martian disk is in arc seconds. It seems that the least illuminated phase is about .842 or 84.2 percent illumination. Full illumination is 1.0, and 'half illuminated' is 0.5.
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