In a filing last week, attorneys for the states and consumer class put Apple’s estimated damages for its role in an e-book price-fixing conspiracy with publishers at nearly $308 million.

The latest figure was derived by a team of economists led by Roger E. Noll, a Stanford University professor emeritus. Beyond the eye-opening damage calculation, however, Noll’s report offers a look at the size of the e-book market in the U.S.

Using transactional records and sales data from Amazon, Barnes & Noble, Apple, Sony, Kobo, Google, and Books-A-Million, Noll determined that 1,348,121 e-book titles (excluding textbooks) were “purchased at least once” between April 1, 2010, and May 21, 2012, with the top four e-book retailers—Amazon, Barnes & Noble, Apple, and Sony—accounting for 98% of sales.

The data collected by Noll points to an explosion of titles published digitally by indies and self-publishers. In all, Noll ascertained that just 83,463 titles—roughly 6% of the total e-book titles sold during the two-year period—were sold by the five settling publishers. In terms of revenue, however, the 6% of e-book titles sold by the five major houses (excluding Random House) generated more than $1.54 billion.

It remains to be seen how Noll’s damage calculation holds up under fire from Apple’s attorneys. But his revenue calculations alone certainly offer perspective on the growth of the e-book market during the litigation period.

Noll declined to elaborate further on the data, and told PW that he was under a court order not to share details of retailer market share.

E-book Revenue and Damages, by Publisher: April 2010-May 2012

*Based on transactional records and sales data from Amazon, Barnes & Noble, Apple, Sony, Kobo, Google, and Books-A-Million, plus projections for a limited time period.

**Weighted average of the effects of collusion on e-book prices, expressed as a percentage of actual prices.