Just a javascript parsing question

Currently making a voting app for a event. Need advice

This needs to be in JAVASCRIPT

I am trying to parse an html table for ever count the number of times each value (beginning with the phrase “board”) appears, it be something like this

board523
board52
board523
board52
board33
board33
board523
board52
board523
board52

In the application, I will not know which numbers exist and which numbers do not, this is what is causing me trouble, I do not know how to do this

sorry if the grammar is bad I wrote this right before I went to bed.