I said "barely".
As others have said, all the estimates we have from research are really low, biased (having been pulled from a tiny portion of the population, i.e. prisoners, rather than a broad group of ages/sexes/locations which would make for a better cross-section as far as accuracy) and likely STILL under-reported because normies would put us in the same category as pedos making respondents very unlikely to self report as zoo.
Also I feel like the fact that references to it in the mainstream SEEM to me to be on the increase suggests at least more interest/curiosity and that has to translate into at least a few more people giving it a go than when it was much further underground.
TL,DR: More than the studies but less than we, the zoos, would probably like