The hydrophobicities given are the "Scaled" values from computational log(P) determinations by the "Small Fragment Approach" (see "Development of Hydrophobicity Parameters to Analyze Proteins Which Bear Post- or Cotranslational Modifications" Black, S.D. and Mould, D.R. (1991) Anal. Biochem. 193, 72-82).
The equation used to scale raw log(P) values to the scaled values given is as follows: Scaled Parameters = (Raw Parameters + 2.061)/4.484.
The work above is summarized here.