My apologies: when the data file is parsed and the @StatsArray is populated, region numbers will be totally random. So the region numbers are sparse, hence @{$StatsArray{$RegionNumber}} works. (Each region is ultimately *processed* sequentially after I am done with the data file.)

Thanks for the explanation, too. I have found hashes of arrays of hashes a little confusing in the past, but I finally have a good, functional example to leverage for future efforts.