Help with student Retention Rate

[angelinadas888]

So I am trying to find the retention rate for students that are returning to the college.

I want to find unduplicated headcount of studnets count once per year regardless of their major, or double major.

Also in this data the new students are given same studentType as Returning

Also find retention rate of student that are returning every year and  - the sudent that have (withdrawn and graduated, transfered)

The one who has dropped their name is not repeated again in another year their last name and studentType will still be Returning.

Below is a demo spreadsheet of my data

https://docs.google.com/spreadsheets/d/1GODRZWBBxoHuRdqKLi-ijUcCJc23lFHgc21Yrv-_blY/edit?usp=sharing

[lbendlin]

Based on this chart, how do you define retention?  Appearing in consecutive years?

So r1024 would still count as returning in 2017 and 2018 ?

[angelinadas888]

In 2017 and 2018, r1024 will be withdrawn as r1024 didnt register for returning. This data I have been given is weirdly set up. So I would calculate the retention by retained students like the ones who are retuning- (the last time returning or graduating or Transfer ones) and divide it by total enrollement that includes all returning,Grad and Transfer. this is what I came up thinking of how I should do it for the consecutive years. What are your thoughts on this 

[lbendlin]

not sure how that would work with r1033 for example?

[angelinadas888]

Similary r1033 last returning will be the withdraw