My guess would be 1:5 or 6 at best as the pike was by this point only there as a defence against cavalry. The only exceptions to this would be newly raised formations which lacked sufficient fire arms these could well have been all or mostly pike.
I am also of the mind that such formations would have tried to replace pikes with firearms as quickly as possible & that the
Boyne was well into the campaign if I recall correctly.
This is where
Beneath the Lilly banners is so cunning as pike bases are really only markers signifying the presence of pike in a unit & with the rules having no fixed figure to man ratio you dont have to worry about ratios.
Ginger