I found a scan of a Birdstudio guidebook saying that USSJ multiplier is 10x.At first,it sounded far fetched to me.But,
come to think of it.Initial Perfect Cell seemed to have a trully enormous advantage over Vegeta,shrugging off a full
power kick on the neck.So,can it be like this...
ASSJ Vegeta/Trunks:1
Initial Perfect Cell:8-9
USSJ Trunks:10