Incremental increase in length dynamic component

I have a pretty good grasp on dynamic components but I’m still getting used to dynamically copy/arraying something in the x and y hopefully my question makes sense.

Using the grid example to create and array of 3 columns x 3 rows, how would I incrementally increase the lengthZ only in the Y direction say by 2" each item? what would Length Z formula look like?

Thanks.

My current formula for Length Z simplified looks like this:

=N+(COPY/copiesx)*(2)

Sorry, I figured it out;

Should be: LengthZ=N+FLOOR(COPY/copiesx)*(2)