Telescope over-subscription rates may be useful in documenting your achievements for promotion and tenure, or planning research projects. This list is based on responses to a FB discussion started by E. Glikman.
NOAO observing Request statistics for 2015A. Includes CTIO, KPNO, Gemini and other community resources allocated by NOAO.
Gemini 2005B to 2014A: Statistics for Gemini North and South, with information for each international partner.
Subaru TAC Report 2014 (PDF): Also includes information on time-exchange programs and graduate student use.
ESO Proposal Pressure: ESO provides telescope over-subscription information and also breaks down the proposal pressure by RA.
NASA Information: NASA's space telescope over-subscription rates can be found in the annual reports to the NAC Astrophysics Subcommittee. The 2013-14 statistics for Spitzer, Swift, Fermi, Hubble, Chandra, K2, Sofia and various grant programs can be found on page 28 of this presentation (PDF). HST Cycles 1-18 information can be found on page 6 of this STScI report (PDF).