Not a direct coorelation, but there is certainly a dependence on being capable in mathematics. A math wizard does not make a good programmer, but one cannot be hopelessly average in math and be a talented programmer.

Actually it really depends on what math skills you talk about. Is it really the material you are taught and can apply to software that brings a lot ? The ability to solve problems ? The culture of correctness ?

The common ground between math and programming is the requirement of a very good capacity to manipulate abstract concepts in a defined frame of known validity. But it pretty much stops here. In mathematics, you define all your abstracts concepts and frame of validity, in programming, you are given a (very shaky and detailed) frame of validity on which you build up abstract concepts.

The ones that are good in approaching the discipline through the study of details to build up stuff that will work on top of it will make the developers. The ones that needs a strong and well defined frame for their work, for it brings a much more powerful ground and enable to reach very high levels of abstraction, will feel more comfortable on mathematics.

No wonder why those that can combines both of those approaches can yield stunning results.

Average of what? I'd bet 80% of 40-year-olds wouldn't be able to pass a high school level maths exam.