Good Morning Jeff,

Here is my explanation:

We have zero for rownum 1. I want to keep this as zero as we dont have data for AOD= 2007-12-01(Previous month of 2008-01-01). This zero should be there for rownum 6 ,11, 16.

rownum 7 should be updated with the amount in rownum 2 which is 50

rownum 12 should be updated with the amount in rownum 7 which is 50(the value we just updated)

rownum 13 should be updated with the amount in rownum 8 which is 30

rownum 17 should be updated with the amount in rownum 12 which is 50

rownum 18 should be updated with the amount in rownum 13 which is 30

rownum 19 should be updated with the amount in rownum 14 which is 20

Thanks a lot for the your time to solve this. I really appreciate it.

---Neela