We can be a bit more specific. Towards the extremes a binomial distribution gets a variance close to the mean (it basically becomes a Poisson distribution). So

We can be a bit more specific. Towards the extremes a binomial distribution gets a variance close to the mean (it basically becomes a Poisson distribution). So that would be a variance of around 600 in this case. All in all a standard deviation of about 0.1 percentage points. This is only a rough estimate but it should give the right order of magnitude.