Cost Center budget plan updating wrongly

Hello Experts,

we have created one layout for CC Budget as per user requirement but the issue is if I am giving any value in a month filed it is updating same value for all month fields and If I am maintaining some amount for each month but it is changing automatically what I have given in last field period(Dec).

Anybody can help where I did wrong and below layout format has created for upload. Advance thanks for your assistance.

Regards,

Sree