You asked

A breakdown of annual population figures during the period of the Conservative / Lib Dem Coalition Government.

A breakdown of annual population figures during the present Conservative Government.

I am particularly interested in : young people under 18 years old; people of working age; people over 65 years.

Net migration figures and of these what percentage are: children under 18; people of working age and of these percentage which are taxpayers; people over 65.

We said

Mid-year population estimates (as at June 30 each year) are available for mid-2010 to mid-2014 by single year of age and sex. Population projections are available for mid-2015 and mid-2016 by single year of age and sex. These datasets cover the period of the Conservative/Lib Dem Coalition and the present Conservative Government. The age ranges under 18, 18 to 65 and over 65 year olds can be aggregated from these datasets. See links below:

Mid-2010 to Mid-2012 - (Table MYE6PE3_mid-2001-mid-2012-unformatted-syoa-data-file.xls) https://www.ons.gov.uk/file?uri=/peoplepopulationandcommunity/populationandmigration/populationestimates/datasets/populationestimatesforukenglandandwalesscotlandandnorthernireland/mid2001tomid2010/mid2001tomid2012ukpopulationestimates.zip

Mid-2013 - (Table MYE2_population_by_sex_and_age_for_local_authorities_UK.xls) https://www.ons.gov.uk/file?uri=/peoplepopulationandcommunity/populationandmigration/populationestimates/datasets/populationestimatesforukenglandandwalesscotlandandnorthernireland/mid2013/ukmye2013.zip

Mid-2014 - (Table MYE2_population_by_sex_and_age_for_local_authorities_UK.xls) https://www.ons.gov.uk/file?uri=/peoplepopulationandcommunity/populationandmigration/populationestimates/datasets/populationestimatesforukenglandandwalesscotlandandnorthernireland/mid2014/ukmye2014.zip

UK 2014 based projections https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationprojections/datasets/z1zippedpopulationprojectionsdatafilesuk

ONS do not hold data on the number of taxpayers.

You can also contact HMRC for advice on this topic https://www.gov.uk/government/organisations/hm-revenue-customs