Standard R3 report in SAP BW

Dear all,
I need to design the standard R3 report T code: S_ALR_87012284 financial statements in SAP BW in a bit customized way.

I am bit confused about which base tables are being used in the report .  Would any body suggest on this ?

Also this standard report, isnt  it a cumulative one? that is it always shows total of all reporting fiscals?

Are the reporting fiscals = 16 in  this report.
Requirement is to design the report  for each fiscal period.

I have used  0fi_gl_1  extractor but I am not able to get the desired result. i thought base table should be GLT0.

Please suggest.

Thanks !