You can easily look it up yourself.

   Early musical training appears to be necessary but not sufficient for the development of AP. Forty percent of musicians who had begun training at ≤4 years of age reported AP, whereas only 3% of those who had initiated training at ⩾9 years of age did so. Self-reported AP possessors were four times more likely to report another AP possessor in their families than were non–AP possessors. These data suggest that both early musical training and genetic predisposition are needed for the development of AP. 

https://www.sciencedirect.com/science/article/pii/S000292970...

this is a brain thing, it appears that the neural parts for whatever is going inside to have absolute pitch can only be formed when the brain is still developing as a child.