adding a Sub total row

I have the following data set

I want to run a sub total row for each year's transactions:

here's how the data looks :

this is the desired output:

one last remark, I want the expression to be dynamic not just a reference for those 2 specific years

and note every 4 rows repeat for each year

any thoughts ??

Preparation

Accepted answers

Here is how you can do it.

Workflow:

Hope this helps : )

Can you provide some sample input and expected output it will help us get a better understanding of the usecase.

this is the sample data with the desired output row highlighted in yellow

Here is how you can do it.

Workflow:

Hope this helps : )

yes that worked right away I appreciate it

I just have one more question

would this workflow still work If I added more years like 4 rows for 2017,2018 and so on or do I need to modify the formula ??

It should still work with no code change.