Type A blood is the most common, the most widely distributed and the largest. In many countries and regions, more than 90% of cats are type A blood, even if it is less, it will reach 70%. So it is very likely that your cat has type A blood, and Siamese cats all have type A blood.
Compared with type A blood, type B blood is less in quantity and unevenly distributed. Common in some varieties, such as 46%~60% in Turkish angola cat. Some species are almost impossible to find, almost 0%, such as Russian blue cat.
Cats with AB blood are very rare everywhere, even rarer than panda blood, which is called "dinosaur blood".