Haplotype caller AF - How to obtain the real AFSpectrum.

Hi GATK team,

I just figure out recently that the vcf I produced with HC was producing theoretical allele frequencies. But I would like to have an allele frequency per population (I can always sub-devide my vcf if needed) and I was wondering if there is any way to get this done via GATK or if you knew a way to obtain this information,

Thanks a lot in advance,
Stooff.