I don't think anyone (possibly not even Tesla at this point) has complete records on percent lost.
I think with 2g network shutdown, Tesla may have lost contact from these Roadsters, so no way for them to keep tracking ones that go offline.
This thread gives a look at some wrecked Roadsters that happened to show up at public auction and get noticed, but there are many more "off the radar" we don't know about. We also don't know for sure how many of those wrecks may have been repaired and put back in service.
So, I think it would just be speculation at this point to try to estimate some number. I haven't even tried to calculate that.