Sport and mental health.

[CapnAwesome]

Not sure what stats you are looking for exactly. Your question is very vague.

How significant are benefits of sport to mental health? If they are significant, would be awesome to know in percentage.

Percentage of what? I'm still not exactly sure the question. There are a massive amount of different stats on the subject. Here is a study about exercise and depression.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC474733/
Jogging moderately 3 times a week for half an hour is as effective as pychotherapy and more effective than ssris.

There were no significant differences between these 3 groups, with all groups displaying a significant reduction in depression, and the positive benefits were still present at the 4-month follow-up (BDI reduction of 10.9 [running] vs. 11.0 [therapy] vs. 7.7 [combined]; main effect for time, p < .001; group × time interaction, NS, p > .05).

Personally though, I cured my anexity disorder with rock climbing. In college I had an extreme case of panic disorder. I had terrible panic attacks and nothing worked. Then I got addicted to rock climbing and they went away almost completely.

For whatever reason depressed people are extremely resistant to the idea that they depression can be cured by sport, it's too simple, even though all the evidence suggests that exercise is one of the best treatments there is.

I'd say that study is pretty limited, because it only studies what I'd call extremely moderate excercise. Joining a sport or doing a sport is the best thing a depressed person can do. Because it's both exercise and social and a good way to meet women and sustainable. Where as just going to the gym is lame and temporary unless you like going to the gym.