Noting this is an Emirates A380 seat map and each carrier will be different but from front to back it is (numbers rounded):
Main Deck all Economy- WC x 4 in the nose
- 76 pax
- Galley
- 135 pax
- WC x 3
- 188 pax
- Galley
- WC x 3
- 62 pax
461 pax to 10 WC = Ratio of 46:1
Mmmm, that sounds like fun.
Upper Deck, First and Biz- WC x 2 in the nose
- Galley
- 14 First pax
Ratio of 7:1
- Galley + 1 WC
- 58 pax
- bulkhead
- 18 pax
- Galley
- WC x 4
- Galleys
Ratio of 15:1
I cannot be bothered to check out the Pax:WC ratios of their existing a/c. There is no doubt that Y will continue to be deserving of it's name Cattle Class.