Eh... I dunno. 85? I have my moments. Also, 你 should say "On a scale of 1 to 100, how mature do 你 think 你 are, with 1 being "completely immature" and 100 being "completely mature"? (Or vice versa.) Otherwise, someone might say they're a 10, thinking they mean "very mature," when 由 someone else's reckoning, it means "very immature."
I guess...umm.. 45 below? idk, all I knew is when it comes to myself, I'm so childish like, watching cartoons, I fight w/ my brother----like 猫 and 狗 do....and many more! but when it comes to others, like mom, weird classmates, my idol...well, simply as matured I think.