how can I get an aggregation like max() for multiple happenings over a diffenrent periods?

[GDude]

My results are in the following table:
happening time_duration Aufnahme zaehler_anzahl

1 50.405 Tasche4 685
2 48.414 Tasche3 629
3 63.486 Tasche2 700
4 50.392 Tasche1 618
5 49.405 Tasche5 689
6 49.348 Tasche4 614
7 52.479 Tasche3 694
8 49.379 Tasche2 647
9 51.425 Tasche1 687
10 50.437 Tasche5 638
11 51.516 Tasche4 675
12 62.422 Tasche3 681
13 54.421 Tasche2 682
Now I have the problem to get key-values for every happening followed by an amount of zaehler_anzahl. The curve in this period you will see in the following Picture.

At the end I want to habe all these periods separate to do further analyses.
Thanks in advance for your help.
George