How do I reduce my observation data and retain every fifth observation?

AQTESOLV for Windows Knowledge Base

For pumping tests, choose Edit | Obs. Well | Edit. For slug tests, choose Edit | Slug Test Well.
Click the Observations tab (v. 3.0+) or the Edit button (older versions).
Click Filters to view filter options.
In the Observation Filters, check the option for Retain every … observation and enter a value of 5. Click OK.
Click OK to proceed with the filtering operation.
AQTESOLV for Windows displays the number of observations filtered and retained. Click OK.