Bluebulb Projects' The Measure of Things presents:
68 is about half the number of Union Stations in the United States.
In other words, it's 0.5040 times the count of Union Stations in the United States, and the count of Union Stations in the United States is 1.980 times that amount.
(a.k.a. Union Terminal; a.k.a. Joint Station; a.k.a. Union Depot) (2016 figures)