Get data from PLMK with data from QALS and QAMR

Hi,

I was trying to get data from the table PLMK,

using

PLMK- PLNNR = QALS-PLNNR,

PLMK-ZAEHL = QALS- ZAEHL,

PLMK-MERKNR = QAMR-MERKNR

and PLMK-PLNTY = u2018Qu2019.

But apparently PLMK-ZAEHL is not the same as QALS- ZAEHL.

Does anyone know how to get the correct data from PLMK?

Do I need to pass through another table?

THANKS!