Estimating the safety of EUC riding regarding fatalities: the hard part

[Mono]

Giving the context: the fatality rate of cycling is between 10 and 40 fatalities per 1 billion km (in the Netherlands and the US, respectively) and for motorcycling it is about 100 fatalities per billion km. When we want to compare this risk to the risk riding an EUC, we need to estimate the distance EUCs have been travelling world wide, which I call "the hard part".

My two estimates for the distance that EUCs travelled so far, ever, are as far apart as 220 to 1200 million km. This is my reasoning (based on some specific information I collected and on this thread). I estimated the traveled km/day in Paris to 2000 trips x 3 km = 6000km, which makes 2.2 million km per year, assuming Paris accounting for 1/2 of the trips in France makes 4.4 million km, assuming a linear increase from zero over 10 years makes 22 million km, assuming 10% of all trips world wide have been done in France makes 220 million km.

Another path to estimate the travelled distance: the V8 model variations have been sold about 40,000 times,^1 assuming they make 10% of all sells gives 400,000 EUCs sold, assuming 3000km average distance traveled per EUC make 1.2 billion km. 

Using the above cycling or the motorcycling fatality rates, we expect for 200 million km traveled to have seen either 2 or 8 or 20 fatalities so far, or 12 or 50 or 120 fatalities assuming 1.2 billion km which we can compare with (colliding with a vehicle is the main reason for fatal accidents, AFAICS)

which may well be higher in reality due to unreported events. Overall, these numbers seem still somewhat too small and uncertain to draw any conclusive implications on the fatality rate in comparison to cycling or motorcycling. It does look to be in the middle or lower end of the same ballpark. It should also be noted that people ride EUCs in rather different ways and modes which are likely to be significantly different in risk, as are some ways of cycling and motorcycling.

Given that almost 500,000 EUCs have been sold and the EUC FB group has 25,000 members, I wonder how many reports of fatal accidents we may just never receive?

^1 Ecodrift (Russia) sold ~3000 units in 2019 and ~1000 of them were from the V8 model line. 

Edited January 14 by Mono