[Rivet] question about run-averaged histograms

[Raghav Kunnawalkam Elayavalli]

Hi Rivet experts

I would like to get the full run-averaged value of some of my variables (which i store in !Dhistograms) and display that with another histograms. I should be able to just fill in my histograms during the run and in the finalize method, ask for the mean and fill that into my average histogram. But i wasnt able to find any mean function analogous to TH1::GetMean() in yoda https://yoda.hepforge.org/doxy/HistoBin1D_8h_source.html . 
Probably im looking in the wrong place and there are easier ways to do that?
Thanks! 
Cheers
Raghav