Data retention policy - how recent responses are included in the analysis?
If you're on the Basic (free) plan, any responses past one month will not be included in the analysis. This means that if there are responses over a month old, they will not be accessible to you. As an example, they won't count towards your NPS score or be otherwise included in the results.
In order to analyze response which date back to more than one month, you'll need to upgrade to a paid plan.
The Essential plan allows you to access data gathered in the last 6 months.
If you're on the Professional tier, there's a data retention limit of 2 years.
The Ultimate plan allows you to include any responses received in the last 5 years in the analysis.