Can you explain your logical reasoning for why you believe most folks with medical school debt come from well off middle class families? I'm confused because n

Can you explain your logical reasoning for why you believe most folks with medical school debt come from well off middle class families? I'm confused because need based financial aid for medical schools is still mostly loans. My partner who comes from a relatively poor family (they used to be on welfare) had most of their need based financial aid in the form of loans. Out of her residency class the highest % of folks taking out loans were from low to middle income families not well off families. So I'm curious where you got that stat from?