You asked
If possible I am hoping that you may be able to help me with the following information:
How many children are in the UK (younger than 18 years old?) Are these historical figures available annually over 50 years?
How many children are projected to be in the UK (younger than 18 years old?) Are these figures available annually over the next 50 years?
What is the annual value of financial investments made on behalf of UK children (younger than 18 years old?) Is this historical information available over 50 years?
In what forms do these investments take?
What are the numbers of children in the UK that have financial investments (younger than 18 years old?) Is this historical information available over 50 years?
We said
You asked for the number of children in the UK and whether figures exist for the previous 50 years. The figures held by ONS are already published in Table 003198.
This table sets out the estimated UK population by single year of age from 1971-2013 (estimates for 2014 will be published on 25 June 2015) and by quinary age back to 1953 (single year of age figures are not available for the UK prior to 1971).
You also asked for similar figures for the next 50 years. These can be taken from the 2012-based National Population Projections available on the ONS website. Please find attached the documents which includes the principal population projections for UK by single year of age for years 2012 to 2112.
Finally, you asked about information on financial assets held by children.
There is only limited information available from ONS sources with regard to financial investments made on behalf of children.
The Wealth and Assets Survey (WAS), which collects details of household investments, does have a limited amount of data. The survey does not collect the value of annual investments but collects the total value of investments held at the time of interview. Although the survey collects information from individuals aged 16 and over (not in full-time education), one adult is asked about the investments held by any children in the household. This is reported on in the Wealth in Great Britain report, Tables 5.5 and 5.6. The WAS has only been available since 2006/08, and currently to 2010/12.
Further information on particular types of financial investments made on behalf of children (e.g. Junior ISAs) is available from the HM Revenue & Customs.