Prob of fatality = 1/40000000

Prob of not fatal = 39999999/40000000 (using 1 - prob of fatality)

Driver makes 5000 drives

you can model this using a binomial distribution

X ~ B(5000,1/40000000)

Probablity that he has n fatalities =

50000CN*(1/400000000)*(39999999/400000000)

Hope this helps. Im not sure if this is correct but it is what i would do. NB: i approximated at the number of zero's as I was in a hurry. Alter as appropriate)