Countifs across tabs and every other column

Hello everyone,

I'm new to this forum but hope someone can help. (Spreadsheet Attached)

I work in a school where we have students studying OCR Courses ranging from Numeracy to ICT and everything else and there is a tab/sheet for each subject. I have built a tracker to enable us to monitor progress, each unit number has two columns a mid year which shows traffic lights (3 = green, 2 = amber, 1 = red, 0 = off/black) then next to that is a unit completed which shows a tick when the number of credits that unit is worth is entered into the cell otherwise it shows a cross.

I want to be able to count how many green traffic lights so (3's) there are overall across all my tabs in the mid year columns but have been struggling as some of the the cells under "unit completed" also contain 1, 2 and 3's.

So I essentially need it to do a countifs formula from columns D7, F7, H7 etc so every other column across every tab/sheet and show it on a summary page at the end so I can see how many green lights are in the Mid years overall. It's probably worth mentioning that every subject has a varying amount of units.

Ideally I then want to count this by year group if possible.

Sorry if this is wordy this is my first major spreadsheet I feel I have done well so far.

5d5cbbc7-6f00-488f-b69b-46d0534a8fa9.png