#SPILL error using named ranges in dynamic formulae

Hi, I am using name ranges.
When projecting numbers I would like to take the previous year number and multiplying them to the respective name range.
However, upon autofill, it does not let me change the cell reference of the year number, so it is just being calculated from one specific year, and not changing to the previous year with each calculation.
ie. I would like to reference the previous column.

Please can someone help me?

G11 is: =F11*(1+RevGrowth), which is correct
H11 should be: =G11*(1+RevGrowth) but shows =F11*(1+RevGrowth)
I11 should be: =H11*(1+RevGrowth) but shows =F11*(1+RevGrowth)
Likewise,
G12 is: =G11*COGSMargin, which is correct
H12 should be: H11*COGSMargin but shows G11*COGSMargin
I12 should be: I11*COGSMargin but shows G11*COGSMargin

I try editing H11, I11, H12 and I12 however the inputs are greyed out. When editing, I get a #SPILL error.

Please can anyone help?