Over this decade and a half, these ten ships (2% of all vessels) made 12% of the voyages, provided 12% of the passenger capacity, and carried 13% of the second and third class passengers from
Europe to New York and back again. [Roughly similar percentages apply to the passenger traffic between Europe and the four largest
U.S. ports (New York and Boston, Philadelphia and Baltimore): there the ten most-travelled on ships accounted for 8% of voyages, 9% of capacity and 12% of steerage and 2nd class passengers. The same ship ranking applies,
except that Cunard's two popular Boston route ships, Ivernia and Saxonia were 2nd and 4th on the list.]
Source: Voyage Database.
For more on individual ships, see: here
and here.