This type of statistics is not available for the selected time period.
Try to open the statistics for earlier dates.
If you think it is a mistake try to repeat the query later or report it to us using feedback form.
Please note that insufficient number of days have passed to count returning visitors with selected time interval, therefore no data.
For the statistics with specified interval: "day", "7 days", "14 days", "21 days", "30 days" data is gathered from a current day on 1, 7, 14, 21, 30 days respectively.
Return Rate is the part of new visitors returned after a certain time.
The return interval is the percentage of the new visitors who returned after a certain time with a selected interval.