Nearly 5,000 CONUS scenes were processed to create LANDFIRE 2010 (representing change 2008-2010). The latest update, LANDFIRE 2012, employed a new image compositing process that used over 20,000 scenes from 2010-2013 in CONUS alone. That is more than 5,000 scenes per year to create composites.
Further Reading:
+ Delivering data for a decade and counting

Webinar Recording Available: Advancing Science Capabilities with Data Harmonization & NASA’s Harmonized Landsat Sentinel-2 (HLS) Products
This webinar provides an introduction to HLS data, services, and tools and shows you how to find resources to work with the data; visualize, search for, and access the data through NASA Worldview and Earthdata Search; it also demonstrates how to use the Fire Information for Resource Management System (FIRMS) tool to visualize HLS data to monitor fires and floods.