Currently, when evaluating a frequency report which has a filter applied that yields no results (e.g. all running process instances when there are none), we return a NumberResultDto with the data value of `0`. For consistency purposes with how we handle e.g. duration reports (where `0` indicates a duration of 0ms and `null` indicates that there is no duration because the task has not been run), we should aim to also return `null` here in the cases where there are no results.

AT:

• reports which return a count always return null when the evaluation yielded no results

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