I think its a small number like 3 - 5% even some if tbe great authors recieved piles of rejections befor hitting it big. you might look into smaller less known presses and epublishers. Ebooks are big and getting bigger.
About 0.03% of all manuscripts submitted in the publishing industry in the US each year actually get published. This means that out of every 10,000 manuscripts submitted, only 3 are actually published.