I don't know the stats, but life vests can also cause loss of life in an emergency evacuation if passengers inflate them too early and this prevents people from getting to/through the emergency exits.

I always go a little bit crazy when the safety announcement/video says that premium cabin lifevests can be found EITHER under your seat OR under the center armrest OR adjacent to your seat OR *somewhere on the aircraft* I suppose. Why can't they just specifically state where to find the lifevest on the particular aricraft type? It's especially annoying when the video seems tailored to the aircraft type on other features or (increasingly rare but worse) when there's a live safety demo by the FAs.