How to improve this sentence? "Replaced over 30% of equivalent workload of supervisor daily..."

Hi everyone, I was previously an intern with a securities firm, and am now trying to add this experience into my CV.

During my internship I did over 30% of my supervisor's work and so reduced more than 30% of her workload.

I wrote in my CV, "Replaced over 30% of equivalent workload of supervisor daily in brokerage activities",

but I just feel that it doesn't sound right. How should I change it? (grammatically and in terms of style)

Thanks!!

Jacky