How to automatically delete the unused lines in google spreadsheet and add them when needed?

Question

I have this google spreadsheet:

https://docs.google.com/spreadsheets/d/1evGqRs8bya68a5aKcn8Yuyk-v3KKBpzAwwZRzhB4XQI/edit#gid=125092189

In the tab CANDIDATS, how do I delete every unused line? Its a chart but every information is automatically generated when someone does the form, and depending on his answers, its gonna go in the right section.

But the sections are way too big when theres no information. I want to delete the lines with no information, to the minimum....

The section 5 (lines 9 to 48) should only have 4 lines if theres 4 lines that match that section... If not, then delete the lines. When a new date fits this section, add a line.

Thank you !