DR Critical Damage Lead

Darth Revan's Leader states: "If all allies are Sith Empire at the start of battle (excluding summoned allies), Sith Empire allies have +50% Critical Damage (Citation)."

How is the percentage applied? Is it fixed or dependent on the subjects starting Critical Damage (CD) E.g. if my Malak has 50% Critical Damage, does DR increase it to 75% (he boosts Malak's CD by 50% of itself) or does Malak's CD go up to 100% (DR gave him an additional, fixed 50% of CD)?

Thanks for the clarification, y'all.