Keyword or keyphrase density on Google

[kostis]

Hi

Since keyword density is clearly affecting the ranking in SERPs, and is a complex metric which is decomposed in densities for visible text, Title, meta tags etc,

I was wondering:
- how much higher is the weight on visible text density than the weight on title density.

- how keyword density weight is compared to keyword proximity weight,

in the G SERP production algorithm.

I guess this is not disclosed, but there should be some empirical conclusions in the community.

K