In your class roster, you will see a DB percentage on the right of each student's name. This percentage reflects a student's Daily Beat completion rate and is based on the number of completed Daily Beats divided by the number of total unlocked Daily Beats.
For example, in the picture above, the course is on day four and there are a total of four Daily Beats unlocked. Student 7 has a DB percentage of 75, meaning they have completed three of the four unlocked Daily Beats. Student 3 has a DB percentage of 25, meaning they have completed one of the four unlocked Daily Beats.