But in this case it wouldn't be a vowel because according to Oxford dictionary, it depends on when you use the letter. For example, in myth it can be a vowel because it sounds like an "i" but in young or Yemen in this case it isn't as you can't interchange it. Link: http://www.oxforddictionaries.com/us/words/is-the-letter-y-a-vowel-or-a-consonant
In Spanish, we consider it consonant, and if we do consider it as a vowel, then it is when it sounds like an 'i', like Uruguay. IDK for other languages.
https://en.wikipedia.org/wiki/Close_front_rounded_vowel
Nice quiz by the way.