Hi Anwar,
I dont think so you whole year data in Logger database or even in HDS, there is retention period and purging system in ICM which remove's extra data based on threshold.
Still if you have complete data in HDS DB, you can find total numbers of call in Call_Type table then termination_Call_Detail table.
First you need to find total calls in a day then highest numbers of calls in one hour per day. you can add days as much as you want. I hope using that mathod you will be able to find the BHCA.
I am not very good in reporting, so just tried to comment on top level.
Thanks
MAR