Avoiding empty stats/metrics

[JerryAclan]

for a webrequest : ads-api.twitter.com/1/stats/accounts/:account_id&…&segmentation_type=CITIES&country=xxxxxx

Is there a way to do this without iterating through a list of Countries?
I mean, is there a way to know beforehand as to which countries will have stats/metrics ?

thanks.
-jerry