Question from the English : Email reading test

Email :

From: Michael Müller <[email protected]>
To: Jean Dupont <[email protected]>
Cc: IT Team <[email protected]>
Subject: Project Status Update

Hi Jean,

I wanted to provide an update on our current project. Here are the key metrics and progress details:

1. The project completion rate is at 70%, with most of the critical tasks completed.
2. We have encountered a 15% increase in the number of bugs reported, totaling 23 bugs.
3. Our team's productivity has improved by 10%, now completing an average of 8 tasks per day.
4. The client satisfaction score has increased by 5%, now at 85%.

These metrics show good progress, but the increase in bugs is a concern. Let's discuss strategies to address this in our next meeting.

Best,
Michael

Which number indicates an improvement in the team's productivity according to the project details?