Ok then, lets go with the number of ships. I'm willing to take a gander and suggest that the amount of ships which passed through the Straights of Dover during the Second World War is greater then that same number during the First. Do you think that's an accurate presumption?
EDIT: I've gotta catch up on some sleep so I probably wont be able to respond for a bit.
I would say that despite ww2 last 2 years longer less hulls would have transitted through the dover narrows. The reason is all the small coastal ships on what are basically domestic transport tasks. These ships are often 1000t or less, uboat sinking logs are full of ships of less than 1000t which is why they used deck guns so often.
This is Britain's great vulnerability, that uniquely among the combatants her domestic transport was vulnerable to sustained enemy interdiction. On top of this of course is international shipping, both in Europe and transatlantic.