The graph shows the percentage of papers using ESO data obtained by the team of authors ("without Archive data usage"), obtained from the ESO or ALMA Archive ("Archive data only"), and obtained partly by the team of authors as well as from the ESO or ALMA Archive ("Archive + PI data"), respectively.
For APEX and ALMA, only papers based (entirely or partly) on ESO time are included.
Information about use of archival data for observations by VLT/VLTI and Chajnantor facilities is available since the start of operations of the respective telescopes and instruments. For La Silla facilities, this information is only available starting in publication year 2000.
Current year only shown as of July. Statistics for a given year will not be complete until approx. March of the following year.