Well I don't have Excel (I'm using Libre Office, and exporting from there doesn't always seem to work well), which makes this a bit more difficult.
I can add a column with the number of reviews, no problem. I was already thinking about it myself to be fair to keep track of all the ratings later on. I'll keep those /5 for latecomers who might just skim over the OP just to be sure.
You can try Google Sheets, it's online and you can copy and paste the table to the OP.