I don't understand the context of the question.
If you search by square footage of warehouse space you will find an answer, that is a better way to look at, because the warehouse count doesn't mean anything.
Also keep in mind that are plenty of warehouses being built and also warehouse operators going out of business, so it is difficult to tell accurately, however it can be quantified in terms of square footage space.
Googling warehouse space in square footage will give you a quick answer.
Also che...