The ever so popular Walmart growth map gets an update, and yes, it still looks like a wildfire. I've added openings up to the planned one in Virgina (in May of this year) as well as openings for Sam's Club, the Walmart-owned warehouse club. Hawaii, Alaska, and Puerto Rico locations are in there too now.
As you might expect, Sam's Club locations appear to trail Walmart locations (except in Hawaii and Alaska).
What you might not expect though is all the Puerto Rico locations. I didn't realize it was so popular there. They got their first one in 1971, well before the first California location in 1990. Whether that's a good or bad thing is debatable.
Check it out for yourself. See any interesting patterns?
P.S. You can find out more about how this was done here, and download the (outdated) code here.