Cannot replace #Div/O error

Dear Members,
I am using a worksheet based on which I need to make a pie chart. There are three main columns Last Serviced Date, Todays Date and Minimum Service Interval. The columns Minimum Service Interval has number 1,2,4 or is blank. The idea is to have these three values is my formula column. Maintained when difference between dates is <365, Not maintained when difference between dates > 365. What I am trying to do is put a formula which would do the following
1.If Difference between Today's Date and Last Service Date > 365, then fill cell with Not Maintained
2.If Difference between Today's Date and Last Service Date >365/(Minimum Service Interval), then fill cell with Not Maintained

This is where the complications start
In the second condition I want to be able to say if Minimum Service Interval is Blank, then use first condition, and fill cell with Not Maintained. Finally if the conditions above are not satisfied then fill cell value as maintained. I have attached an excel sheet to give some clarity