Mine ( Musicsharing4u) is the same,lots from google and little from yahoo. i think there are much more people use the search engine of google than yahoo. Then the key words rank for google and yahoo are not the same.
Yes, Yahoo is not used as much as Google and that's why if your website displayed top in yahoo you can not get the as much as traffic for your website that is reason why you have not getting well traffic for your website.