Actually sperm count is 50/50 x and y in equal amounts.
I don't believe that is true. I did research into this when we were expecting number three after already having two children of the same gender.

Not all men produce x and y sperm in equal amounts. Some men do, some men produce more x than y, and some men produce more y than x.

You are more likely to have three of same gender if your first two children are boys as nature slightly favours baby boys.

TICKLISH