A quick google search for yields per sq ft gave me the results I...

A quick google search for yields per sq ft gave me the results I pasted below.
So the average 39.5 grams per sq ft = 790kg for 20,000 sq ft average.
The best result was 60 grams per sq ft = 1,200kg
Now that is per harvest, they would be lucky to get 4 harvests per year, so x4 = 3160kg average up to 4800kg
Rotogro stacked 2 high gives 9,000kg and their figures are conservative based on their test results.
Of course in Canada, you need indoor cultivation because of the climate to maximise the growing season. It doesn't grow well in snow & ice.
These results would include the big boys, Canopy etc

37,000kg must be a typo, just don't see how it would be possible, either that or they're off with the fairies.

https://mycannaapp.com/the-average-greenhouse-yield-per-square-foot/

Greenhouse Yield Per Square Foot

In a piece by the CannabisBusinessTimes, the news source estimated the average yield per square foot.

They surveyed cultivators who run greenhouses that got as high as 60 grams per square feet to as low as 20 grams per square feet.

While that is a big swing from one end of the spectrum to the other, the average was pretty close to the lower end.

The mean for those surveyed was 39.5 grams.