It's very uncommon for eggs to be infected with salmonella.
There's no way to know for sure but the eggs that would likely be infected with salmonella is 1 egg out of 20,000 eggs.
Still even if an egg was infected with salmonella the salmonella will be killed off when you fully cook the egg.
That is the key here you must fully cook the raw egg so that there are no runny parts of the egg and when you do cook the egg fully the salmonella will not be able to survive.
Also if the chicken laying the eggs is not infected with salmonella then the eggs will not be infected with salmonella either.