Accessing TST_HISTORY_DETAIL table for a task

We are using SpiraTeam v4.2.0.1 and need to export the Actual Effort data from TST_HISTORY_DETAL in order to populate another application we are using for time tracking. Although we can see this data displayed in the History tab of a task’s detail, we are unable to see how that data is connected between the TST_TASK and TST_HISTORY_DETAL tables. We have tried to trace Project ID, Requirement, Task_ID, Artifact_History_ID ad Artifact_ID. Please help us to understand how we can extract this data.