People would rarely use "most" for less than a 2/3 majority, and a lot of people (but maybe not "most" of them ;-) would consider you dishonest for saying most in that case. Usually, "most" means something like "all but a small number", i.e., close to but not "all".
Huh? Please consult ANY English Dictionary. :) 'Most' is a superlative meaning the one that is the GREATEST in number, amount, extent, degree, etc.
When you're talking about a binary variable (only two categories as here), then 'most' means a strict majority. If I have two containers and one has 10 jellybeans and the other has 9, I really hope you can determine which container has the MOST jellybeans.
Just my $0.02 :)