Excel formula to Increment every after X Number of Years - excel

Question

I would like to Add an Increment of One on Every X Year Interval
For Example if X = 3 Then the Following Data should be
SG Last Year
5 2010
4 2014
3 2015
6 2016
Would result to
Grp Last Year 2016 2017 2018 2019 2020
5 2010 6 6 6 7 8
4 2014 4 5 5 5 6
3 2015 3 3 3 4 4
6 2016 6 6 6 7 7
So the First Record the Candidate is in group 5, from 2010, in 2016 I would like to calculate if the candidate has a span of at least 3 years if so, push him to 1 upper group which is 6. The Same Candidate will go through n Number of years and every 3 years (X Number of Years) would increment their group till we reach to 1 and continues with 1 without any increment. Thus is the same example since we increment in 2016, the candidate would have the same group for the next 3 years and only in 2019 would we increment again and so on.
I would like and excel formula or process which I could use for the data set proposed

Answer 1

You were almost there.
LY = Last year (that static cell in each row);
AY = Active year (the column for which you are calculating),
G = group (start value),
PR = previous result (for prev year),
R = result (what you want to get),
X = year interval`
You can use one formula for first year (2016) and another for the rest, so you can use previous value PR, not initial group G.
Obviously LY stays constant for the row.
R = IF (( (AY-LY) \ X)==0 , PR+1, PR) - change when mod is 0.
Use #3 formula for all the years except first column (2016).
For first column (2016) instead of PR you should use G.
To have a constant cell, you write in form of $A$1 (for G)
For constant row you write in form of C$0 (for AY)
Your formula was almost correct. And you need to set the values constant where they need to be.