projection on enrollment

What would be the best approach on the data for projections/analysis for the sample data. and graph representation..
There will be other 2 sheets for senior and college
uploaded file.
Thanks

It very much depends on what you are trying to show. What within the data do you need to analyse and highlight? Is it the ratio of boys to girls? Is it the fluctuation in numbers from year to year? I'm afraid you have not been specific enough.

It's the year to year fluctuations and possible Trend analysis. Data would be continuous.( yearly )

I am guessing about what you want to analyze as far as year to year trends.
1) I115:I124 identify change in percent between the Grande 5 and Grade 6 years for the classes using: =F115/F101-1
2) K125 calculates the anticipated differential for class #6 using: =LINEST(I115:I124)
3) Based on the anticipated differential, cells D125:F125 project the enrollment in Grade 6 for the 2019-2020 term
A table and chart, rows 35:48, follows the progression of enrollment of classes on the Elementary sheet (Note that only classes 1:5 have completed all grades). To see a different class change the number in cell I35.
I hope that this will stimulate some responses from the more mathematically inclined members, however I imagine that they would like to know specifically what trends you want to see.
Let us know if you have any questions.

If the summary from the Junior will be collated, such that the data will be continuous from Prep to Grade 10. How can we do that, since the dates started only in 2014-2015.. (The feeder in Grade 7 are from Grade 6).

Thanks

I applied the same logic to the 7th grade however I am not sure that the output has much meaning. Notice that the correlation between total enrollment in the 6th grade for the 2013-2014 through 2017-2018 terms and the 7th grade for the 2014-2015 through 2018-2019 terms is only 0.051379 which is extreamly low. The line graph also seems to indicate that there isn't much relation between the two.
On the other hand the correlations between the other grades seem strong.
I would still like to get some input from one of the mathematicians on the board if possible. I may put a note in the 'Call in the Calvary' thread.

Thanks I'll wait for other possible additions to the solution using your last upload by other members.