Function to identify /Allocate next 11 months based on current month

User_N9Z3I

I have a requirement to calculate data for current + 11 months

If Currmon = Jan

Jan = 75% of 100

Feb:Dec = 25% of 100

If Currmon = Feb

Feb = 75% of 100

Mar:Nextyr->Jan = 25% of 100

IF Currmon = Mar

Mar = 75% of 100

Apr:Nextyr->Feb = 25% of 100

Can anyone help me with the functions to auto calculate next 11 months .