Left panel: redshift distribution of the 69 intervening Si iii absorbers in our sample. Middle panel: distribution of Si iii λ1206 restframe equivalent widths of the 69 absorbers, obtained from the pixel integration over the Si iii velocity profiles. Right panel: distribution of logarithmic Si iii column densities for the 69 absorbers, derived using the AOD method. The gray-shaded area indicates lower limits for log N(Si iii) for absorbers that have saturated Si iii λ1206 lines.