In the US the most common deployed size is below 5MW?

Dont know why i can't reply to the person commenting below. But where's the statistics? Who has these datacenters out in the field?

Yes, but that's not where the volume is. A 'small' data center, even here in Europe has 100's of racks. There are of course many tiny ones but collectively they don't even add up to one single large Google or AWS DC. Those things will run in excess of 1 or even 2 GW.