Yes i corrected it before your post, i punched the wrong number (132 instead of 142) into my calculator
So yes it is ~33.8% - 61.9%
I think realistically, if that rather ropey looking slide is true, it's likely going to be roughly around 3080 performance with the standard variation you get between games. If they have started at "1.9", knowing marketing speak, it is likely more often than not 1.9x faster than the 5700xt with a few games netting a bigger increase.
At least it will have 16gb of vram though, and it will be interesting to see where they price it. They could really take it to Nvidia if they prices it at £500 or less.