About  Calculation（debit and lender） ！

The result viz like following picture:

I can't finish this viz.

Conditions:

1.The balance is the sum of debit reduce lender

2.Occurrence is debit reduce lender in the period

3.If balance greater than 0, debit reduce lender should be greater than 0 too，else if debit reduce lender is less than 0，the result of debit reduce lender Will be ignored, it will be 0. In other words, if balance>0 then debit reduce lender>0, else balance<0 then debit reduce lender<0.

4."31-60days" should be less balance-"1-30days" ,"61-90days" should be less balance-"1-30days" -"31-60days", and so on. till the result is 0

for example:

Any ideas I appreciate.Tableau 10.3 or Tableau 10.2 saves attachments, both OK。