Finding Phd Specific information might be a little difficult. While a lot of universities post average scores of the admitted students, they rarely specify separate scores for PhD admits.

You can roughly estimate the scores required from the masters admit scores as they tend to be quite close to each other.

You might find this link useful: https://gre.myprepclub.com/forum/average-gre-score-required-by-universities-in-the-usa-531.html