Production Times of the C2 cargo ship -vs- EC2 Liberty Ship

Greetings,
I'm looking for information regarding the production times of the C2 cargo ships build just prior to the introduction of the EC2 liberty ship. And how much longer the first liberty ship took to produce than the say the 100th liberty ship.

I believe the first EC2 ship took longer than the last few C2 ships, regardless of its "express" design. I want to use it as an example of how changes in production always increase the production time at first and then reduce as time goes on... This can be seen in the Willow Run aircraft factory. The factory was built and production was painfully slow for a while but eventually got better and better until they producing 20 per day.

I'm basically looking for production times of the later C-2 ships and the early EC-2 ships.

Any sources or input will be appreciated.
Thanks,
VS

http://www.econ.yale.edu/growth_pdf/cdp905.pdf
Unfortunately I don't have production data concerning Liberty ship construction. However the paper at the above link has production data for German Ju-88 aircraft program.

Ju-88 production cost fell from RM 210,648 during 1940 to RM 131,145 during 1943. I expect Liberty ship follows a similar production cost curve.

Find out the ship names of the first few and last few. Then see if you can find the dates between the time the keel was laid the launching dates.