Can you explain the percentages seen under the Percent tab in the Subscriber Retention dashboard?

If you're looking at the Subscriber Retention dashboard and have the 'Percent' tab selected, you will notice that various percentages will populate columns that start from '0' and can go up to '18' - what exactly do they refer to?

Here is the breakdown:

• Column 0:  The month a subscribers becomes a paying subscriber
  • The subscriber could have had their subscription in trial previous to this month. 
• Column 1: The number of NEW active, paying subscribers. The subscriber could have started paying anytime during this month
• Column 2:  % of the subscribers from the cohort in column 1 that were retained from Day 0-Day 30. Retained means the subscription has not expired. 
• Column 3: % of subscribers from the cohort in column 1 that were retained from Day 0 - Day 60.