https://wikimedia.biterg.io/app/kibana#/dashboard/Maniphest contains some unexpected numbers, which would be a good learning if they were true. However, it seems they are not.
I've checked the submitters table:
|Submitters||Issues||Projects||Assignees||Avg. Open Days|
|[[mw:User:This, that and the other]]||1,304||529||119||392.118|
|Adam Roses Wight||859||363||35||421.15|
|Amir E. Aharoni||819||384||74||423.998|
|Aaron Halfaker, EpochFail, halfak||788||236||56||333.425|
According to a maniphest search, the first user has created / authored / submitted 262 tasks / bugs / reports in total, which is less than 1304.
Are you by any chance double counting reports, e.g. once for each project they are attached to?