The Humane League Labs has published a data set and report in a project titled US Egg Production Data Set that compiles an analysis-ready data on US egg production (with a focus on cage-free housing) and clarifies terminology. I am happy to answer any questions and receive feedback, as we hope these products will be helpful to the wider research community.
Executive Summary: Tracking the capability of the egg production industry to supply the food industry with enough cage-free eggs to meet retailers' and restaurants' animal welfare commitments is important to industry groups and farm animal advocacy organizations alike. In this project, we synthesize an analysis-ready data set that tracks the supply of cage-free eggs relative to the overall supply of table eggs in the United States. The data set is based on United States Department of Agriculture (USDA) reports published monthly from September 2016 to present, with auxiliary annual data from December 2007 to December 2015. The data set will be updated monthly as new USDA reports are released. We supplement these data with definitions and a taxonomy of egg products drawn from USDA and industry publications. The data include flock size and egg production of cage-free hens as well as all table egg laying hens in the US, collected to understand the impact of the industry's cage-free transition on hens. Initial analysis of egg production trends shows that, at the time of publication of this report, 20.3% of all table egg layers lived in cage-free systems. This figure represents an increase of 10.2 percentage points between August 2016 to June 2019, with an increase of 17.1 percentage points over the entire sample period of 2007 to June 2019.