Anyway, here is how I do this:

Column title: Doc Actioned Percent

Count Count Actioned

Column name: $Total $Actioned $Percent

Formula: 1 @If(fld=x;1;0) $Actioned

Totals type: Total Total Avg per doc

Format: Number Number Percent

This only works because the average per doc is only ever 0 or 1 and so at the category level the average will effectively be the percentage of one column total against the other.

To be able to do this for any value would be great but I haven’t seen an easy way yet. Does v7 possibly offer this feature, anyone?