IF Function for Changing Market Share

[habban]

I am rolling out outlets month wise with a certain market share in year 1 (15%) and year 2 (20%).

therefore if i roll out in year 1, these outlets will have 15% market share in year 1 and 20% in year 2.

However the outlets i roll out in year 2 should have 15% market share as its their first year, and subsequently 20% market share in year 3.

i need an IF function for one row, however it would be linked to multiple regional roll outs.

Please advise.

 

[nbrcrunch]

In general terms, you will need the date of roll-out for each site.

Then TODAY() minus date of rollout divided by 365.25 will give you the number of years each site is open. You can use that result to multiply by your "share".