Those two or three numbers you often hear breeders using are a way to represent sex ratios.
If someone says they have "1.3" adult kingsnakes, that means they have 1 male and 3 females.
1.3 = 1 Male and 3 Females
When they use a third number such as 1.3.1, that means they have 1 male, 3 females and 1 that has not been sexed.