I've reread the post, and no such things are stated or implied.
This is the final problem with part p, that deaths can be expected to decline over time regardless of whether pp is in place or not. Without pp they'd decline quicker, since rewiring would be avoided less often, and there would be less inclination to do illegal jobs. But since it should decline either way, future statistics will not tell us much.
In fact unqualified working is common today, but is not a signficant problem, as confirmed by the near zero death rate stats. Often one hears 'ooh thats dangerous cos its not regs compliant' but IRL the risk level is miniscule. If only other areas of daily life were as super-safe as electrical installations.
In the 80s I saw an installation still in daily use from around WW1 (in retail premises as well) so I reckon it'll take an awful long time for our historic installs to disappear. HMG might want us all to give our money to business every 20 years for a rewire, but many arent that easily taken in.
blue & brown
But bear in mind most countries have lower standards to start with. UK wiring has so many layers of protection designed in that errors here and there dont normally get through all those protection layers, thus no incident occurs. Hence our wiring system is much more cowboy-proof than in most countries.
NT