Is your feature request related to a problem? Please describe.
First Issue. I would like to report the speedup (T(1) / T(n)) when using multiple threads with ThreadRange(). There exists ComputeStatistics(), but it only contains values for one specific thread. It seems there is no way to get all values for a single named benchmark. Please correct me if I´m wrong.

Describe the solution you'd like
Ideally, there should be a method similiar to ComputeStatistics() that aggregates all values for all threads.

Describe alternatives you've considered
Maybe access to the State can be provided in ComputeStatistics(). This way, at least each run can be identified by its thread_index and its name. Values can then be stored externally.