Relative timescale in time series chart

  • What Grafana version and what operating system are you using?
    Grafana v8.5.24

  • What are you trying to achieve?
    How could I change the Y-axis to show a percentage change relative to the first (oldest) element of the time series? Prometheus is my data source.

    Using this screenshot as an example, I’d like 0% in to be where 12.8GB is and +6.3% instead of 13.6GB.

  • How are you trying to achieve it?
    I tried using Math/Reduce expression. However there is only “Last” option available, but not “First” for some reason, so I could create a scale relative to the last element (but need it relative to the first).