95% of the general cat population is non-white cats (i.e. not pure white) and congenital deafness is extremely rare in non-white cats.
5% of the general cat population is white cats (i.e. pure white). 15-40% of these pure white cats have one or two blue-eyes.
Of those white cats with one or two blue eyes, 60-80% are deaf; 20-40% have normal hearing; 30-40% had one blue eye and were deaf while 60-70% had one blue eye and normal hearing.
Of the 5% of white cats in the overall population, 60-80% had eyes of other colors (e.g. orange, green). Of those 10- 20% were deaf and 80-90% had normal hearing.
Deaf white cats with one or two blue eyes account for 0.25 - 1.5 of total cat population
Total number of cats with white coat and blue eyes account for 0.75 - 2.0% of total cat population