Number of Report Intervals limited to 20

Hi, my investments go back to 1988. Occasionally I would like to see the performance of one specific year or the performance since a specific year. So I started defining the corresponding Report Intervals, however it seems not more than 20 Report Intervals can be defined. Is there a limit on the number of Reporting Intervals and - if yes - why?
Thanks!

Originally, there was no option to edit the report intervals. In order to prevent the list growing endlessly, I removed entries. Now there is more functionality to edit the entries - I will rework this part of PP with the next version.

Is now published with Version 0.46.1