Help with formulas to perform indexation to rental income on annual, semi-annual etc

All,

Hope you can help me with creating a dynamic formula to calculate indexation on rental income.

I would like to have the possibility to calculate precise rental income depending on different indexation method. Some tenants only have their rent indexed annual, some have it every second year and some third year etc. If indexation everythird year the rental income will be the same year 1 and 2, while rent in year 3 will then be indexed by the inflation the last three years.

I have enclosed a dummy file where I have tried to explain the issue - Ideally I would like to be able to change cell G11 in the attached file and the indexation automatically changes to annual, every 2nd year or third year or even 10 year if the cash flow is long enough.

Appreciate all the help I can get.

Thanks,
Stian