Here’s a useful trick for doing a frequency analysis in Google Sheets or Excel.
A Box and Whisker chart can be a useful way to represent a set of marks.
Peer assessment is a great idea. It means you can get students to really work with the rubric, and in the process learn to self-assess and reflect on their own learning, those super-valuable metacognitive habits of mind.
BUT it can be a logistical problem. 25 class members multiplied by 25 assessments, with say 5 criteria to assess. That's 3125 items of data! What are you going to do with that? Well, you can start by using a Google Form to collect the data, and then analyse the data with a pivot table. Here are the steps to follow: