What is the percentage/statistic of a singer getting signed?

I wanna know cus my friend is being really stupid our convo went like
ths:
Her: All-American Girl by Carrie Underwood...........NOBODY, but me
can sing that song like a professional........I say professional
because my singing career is actually gonna go somewhere (I know for a
fact).
Me: Wow. You're modest. And how do you know for a fact?
Her: did you know that modest actually is a good thing and becasue i
have a WONDERFUL voice
Me: I WAS BEING SARCASTIC. im sorry but this status seems vain and
self absorbed
Her: well maybe i am and if you dont like it you can leave so HA
Me: Ha what? There is no ha in this situation. You either are vain or
you're not. and this status makes u seem like you are
Her: well...then maybe i am so if u dont like that sucks for you
Emma: A lot of people don't like that. Being a vain singer is like
being Sharpay in highschool musical. I never said your singing was
bad, but when you act like ur all that. it's called an egomaniac
Her: i dont but if i KNOW that its going somewhere its a different
story
Me: Yeah. well now you are. lemme point out vain parts in your
statement: "NOBODY but me can sing that song like a professional"
false "(I know for a fact)" False
Her: how would you know if its not a fact......i could have gotten
calls from record companies asking for me i could have met my
celebrity BF JB ♥..you wouldnt know