The chart below displays the number of scenes visible to all users on EarthExplorer as of December 31, 2016.
In addition to the current Landsat 8 and Landsat 7 missions that are constantly increasing the data in the USGS archive, the Landsat Global Archive Consolidation (LGAC) effort is returning unique Landsat 1-5 MSS and TM data originally downlinked to International Ground Stations into the USGS archive, making even more data available to all users.
The files on the USGS Landsat Global Archive webpage provide a view of the data added to the USGS archive per satellite, per year.
This Landsat 8 image is representative of the many scenes downloaded from the USGS Landsat archives during December 2016, and shows the a portion of the Paraná River, a natural boundary between Paraguay and Brazil.
Landsat 8 Image of Path 224 Row 77. Acquired December 1, 2016.
The Landsat archive became available to all users at no charge in December of 2008. As of December 31, 2016, over 51 million scenes have been downloaded by users worldwide.
This graph shows the top ten Landsat data uses from October 1, 2016 through December 31, 2016.