Using Structure Table References in Conditional Formatting formulae

I'm trying to set up a traffic light-like colouring system for some assessment data, but I'm not having any success linking to the numerical conditional data.

I have Norm data in 4 tables, one for each test-type (Mathematics, Reading, Language Usage, Science), which is linked to Grade Level.

I have data in another table, and I want it to be coloured (red for value LESS THAN mean-1 SD, yellow for mean - 1 SD LESSTHANORREQUAL value LESSTHANORREQUAL mean + 1SD, green for value GREATERTHAN mean + 1 SD). The limits will change depending on the grade level, so I want this to link to the correct tables, instead of hard-coding them.

Sample file attached, the reference tables are on the Norms page, you can see the conditional formatting I've currently set up on Sheet2. Problem is that once I introduce Grade 7 data, for instance, this conditional formatting will no longer be valid.

Any suggestions?

Thank you. That's a great solution and SO annoying! I was trying so hard to avoid doing that, but had guessed it might be the case.

Appreciate your input.