Until v9.0.00.xxx there used to be a report type 'WCM Request' that would help with what you're after, but in v9.0.18.xxx bmc removed it.
Maybe you can get this information from the EM database.
I haven't looked into it in detail but try these tables:
DEF_WS_HISTORY --> I think this one
DEF_WS_TABLES --> and this one will give you what you need