Stacks Firing and Morale Checks

[HMCS Rosthern]

If more than one unit is selected and all fire at a target....

1. The Combat Results calculation is performed for each firing unit in the stack, i.e., each unit fires separately.
   
2. The manual says "if the fire result affects the target unit, then the target unit performs a Morale Check". 
   

So my question is, does the target unit take a morale check for each firing that affects it? Or is there just one morale check for the multi-unit fire?