Where is the customer number(KUNNR) stored in VBO3 transaction??

Where/In which Transparent Table is the customer number(KUNNR) stored in VBO3 transaction??

In VBO3 transaction>>Enter some agreement number>>press enter>>Click on Condition button>>select some value and proceed.

Here you will find Customer number(Kunnr).Please tell me,in which table is this value stored??Kindly tell me the procedure to find the same so that I can find In which transparent table others fields stored on this screen......:)

Regards,

Shashank.