I understood it marks weather it is double, triple .. reversal. It does not count number of elections but same value reversal can be generated from multiple events.
https://www.armstrongeconomics.com/uncategorized/understanding-the-double-reversals/
https://d33wjekvz3zs1a.cloudfront.net/wp-content/uploads/2016/02/ModelsMethodologies.SecondEdition.pdf - page 27

Also, if you go with a mouse on that number near reversal you get some explanation.