For what it's worth, that number isn't terribly far off from the roughly 1 in 200 worker fatality rate for the construction of the Hoover Dam in the USA. It would be even closer if we assume for the sake of argument that only about half of Saudia Arabia's foreign workforce is working directly on Vision 2030 projects.
And way lower than the rate of about 1 in 25 indicated by the article you linked on the Canada railway.
And way lower than the rate of about 1 in 25 indicated by the article you linked on the Canada railway.