The rate of golds doesn't suggest any country has better drivers than the others, it just suggests there are more casuals taking part and not finishing it.
Let's face it, for anyone with a modicum of skill the gold times are very easy. The only reason the gold percentages are not all 100% is because either very poor drivers are competing or they're getting bored and not doing all of the tests.
To suggest having a higher gold percentage rate means that country is filled with the best of the best is just wrong though.