Performance

Website usage

Notes
¹ Unique hosts served is the best approximation available to the number of individual users of the website.
² The slight decrease in 2009/10 is mainly due to extensive changes to the Library's website which had a temporary impact on the visibility of individual pages via search engines.
³ The number of pages of all types viewed on the website. Every landing on every page is counted in this figure.

Service in the Reading Rooms

Notes
¹ This includes seats provided at the British Library Integrated Catalogue screens, electronic database terminals, microform readers and carrels (the individual study booths in the Reading Rooms).

Bibliographic services

Notes
¹ Number of unique records. A project to remove any duplication is ongoing.
² Available from the Library's website.
³ Conversion of printed catalogues to electronic versions for inclusion on the Access to Archives website hosted by The National Archives, was completed in 2006/07 and therefore this figure has remained the same in 2009/10 and 2008/09.
⁴ All other Asia, Pacific and Africa Collection material, except for Japanese and Chinese material, is included in the British Library Integrated Catalogue.
⁵ A database listing articles and conference papers by title, derived from the top 20,000 research journals. The database is available through British Library Direct and to Higher Education through zetoc.mimas.ac.uk.
⁶ The total does not represent the number of unique records. There is significant overlap between some files e.g. British National Bibliography and British Library Integrated Catalogue.

Collection development

Notes
¹ The figure for monographs is based on the number of records in the relevant catalogues. This figure includes an estimate of items covered by card catalogues.
² The figure for serials titles is based on the number of records in the relevant catalogues. Changes of title are therefore counted as separate titles. This figure includes an estimate of items covered by card catalogues. A significant project has been undertaken to de-duplicate serial holdings.  This rationalised database more accurately reflects the number of unique titles held.
³ The archives of the India Office (1858-1947) and its predecessors, including the East India Company (1600-1858).
⁴ Digital audio files are now used extensively and have largely taken over from sound tape items.
⁵ Reports in microform are no longer produced as the microfilm service for UK Theses has been replaced by the Electronic Theses Online System (EThOS). This stores and supplies digital download copies of theses that have been scanned in the digitisation suite at Boston Spa.
⁶ Theses are now created, stored and supplied electronically on EThOS.

Items received on legal deposit

Notes
¹ Work undertaken in 2008/09 resulted in a significant increase in Monographs received during the year. Some of this increase resulted from Monographs actually published in prior years that had not been deposited. The 2009/10 figure reflects more accurately the underlying annual rate of deposit.
² The number of items received on Legal Deposit in 2009/10 is lower than in the previous year as a result of work undertaken to remove duplication in the count of bibliographic holdings.
³ The decrease in 2009/10 is due to a reduction in the number of printed newspaper titles available for deposit.

Storage

Preservation

Notes
¹ Working capacity represents the linear length of the solid stock, plus the associated growth spaces without which the collection could not be used and added to effectively.
² The 247 linear km increase in working capacity is explained by the inclusion this year of the Library's new high density storage building. Moves into this building are in progress with those from the three leasehold buildings and is scheduled to be completed by the end of 2010. At that point the leasehold buildings with a total working capacity of 110 linear kms will be surrendered with a consequent reduction in working capacity to 792 linear kms.
³ This is an overall estimate using actual figures that are available, together with estimates for growth for some collections not yet available for 2009/10. The latter is largely explained by the ingest of empty containers and the large scale stock moves into the high density storage building. During this time it has not been possible to add newly processed items, and their associated growth where appropriate, to this location. The information will be captured once routine working of the high density storage building commences.
⁴ Once allowance is made for the reduction of 110 linear kms following the surrender of the leasehold buildings percentage occupied rises to 83%.
⁵ Fluctuations in figures are due to the normal variations which occur annually when treating a wide range of non-standard items with variable resources and priorities.
⁶ This figure is the approximate number of volumes equivalent to the frames shown under the heading 'preservation microfilming'.
⁷ One frame equates to one camera exposure. These generally represent either a single or double page of a monograph, newspaper or periodical.  For most programmes, a negative, positive and duplicate are taken of each page. Consequently the number of frames shown does not represent the number of pages for which surrogate copies have been made.
⁸ The decrease from the previous year is due to a reduction in expenditure on surrogacy programmes for 2009/10 together with an increase in costs.