30F was guessed yesterday, the list I came up with this morning was 13M, 31M, 33F, 37F and 42F. 13 is unlikely, not only because of the VN demographic, but because your post style doesn't seem like that of a 13 year old. 37 and 42 were outlier guesses,so you couldn't have expected them to have been guessed yesterday, which left 31M and 33F, with 31M being more likely because it had a higher chance of being guessed yesterday, and because my intuition told me you were male.
I may or may not have taken this a bit too seriously. >.>