Council and democracy

Registrar General's mid year population estimates

In the 10 year gap between Censuses, the Office for National Statistics (ONS) produces annual estimates of population for local authority areas called Mid Year Estimates. These are based on the numbers of registered births and deaths, and on estimates of migration into and out of the area.

Mid Year Estimates are published as populations by 5 year age band and sex at County, District and Unitary Council levels only. Estimates for a particular year are usually published in the following August.

The latest figures available are the 2007 Mid Year Estimates which were published on 21st August 2008. These show that the population of Hertfordshire has increased from 1,058,600 in 2006 to 1,066,100 in 2007, an increase of 7,500 or 0.7%. The full data for Hertfordshire and the 10 district councils is published below.

A number of experimental mid year estimate datasets have also been made available by ONS giving estimates for Super Output Area and Ward geographies and for Ethnic Groups. These datasets are classified as experimental as they are not deemed official Nationals Statistics but are still in the testing phase and are not fully developed. ONS publish these in order to get feedback from users on the datasets.

For more details of the current estimates please see the ONS website at
www.statistics.gov.uk/statbase/Product.asp?vlnk=601&More=N

For more information on the 2007 estimates please see the factsheet below. Factsheets on previous estimates are also available, even though the data in some of the previous factsheets has been superseded, the factsheets still give useful analysis of trends.

Because of these continual revisions it is important that when working with Mid Year Estimates that you ensure that you have the latest versions.