Bluebulb Projects' The Measure of Things presents:
4,400 is about thirty times the number of Union Stations in the United States.
In other words, it's 32.60 times the count of Union Stations in the United States, and the count of Union Stations in the United States is 0.0307 times that amount.
(a.k.a. Union Terminal; a.k.a. Joint Station; a.k.a. Union Depot) (2016 figures)