>> I'd say 58% is not statistically significant
> 58% is also not weak.
The results you've given here are not in themselves statistically significant (i.e. no correlation was demonstrated), due to the low 8% trend in tandem with the small sample size of a single tournament of 40 results. Or to put it crudely, your comparison here has only 40 results: only three of these need to be anomalous for the error to be higher than the trend.
That's all I'm saying really - I don't quite understand the point of considering one tournament on its own, it's a bit like saying: I've done a much bigger comparison and here is one more data-point for it, let's discuss that one by itself.
> I have compiled these statistics to show just how obvious it is wealth and population effect games.
To look at one tournament separately doesn't really illustrate anything mathematically, it's only with much larger sample size that you can really say something solid about the trends. [I'm not sure whether me spelling this out is patronizing or not, apologies if so]
Conversely, once you have established an overall large-set trend, that doesn't necessarily say anything about the size of the effect in individual tournaments (or matches) which can be viewed as random variables from some distribution the parameters of which may be measurable by your large-set statistics.
> Again, the average for each tournament is 65% which is not a weak correlation at all
If you mean that 65% is the average over all tournaments of all sports (?) then I agree, because that comparison involves many thousands of results, albeit taken from possibly rather disparate distributions per sport and/or era, so the sample size will be enough to imply statistical significance (although it might be wise to estimate the margin of error).
> This means 2/3 of games in major tournaments are won by countries with more wealth/population, this is a huge statistic.
It's not quite that, it means that out of the games *which were not draws*, 65% were won by the team with more [insert bespoke population/wealth combo here]. To ignore draws is misleading, particularly in a low scoring game. Doing this would have almost no effect on, say, rugby or basketball, but draws are a big deal in football.