Selecting an item of every 20 items in a pivot table

Hi friends ! I am new to uipath and I apologize for my English, Could you help, I need to filter the pivot table, for example, in the pivot table, I have a list of companies, there are about 300 of them (may vary) and I need to get only 15 pieces. To do this, I count the number of rows in the pivot (for example 300), divide by 15 and select every 20 row. Can you please tell me how you can select and save every 20 row in the pivot table, and delete the rest?

@Palaniyappan can you help me pls