You asked
I am seeking information regarding the number of registered vehicles in each council for financial years 2018-2020.
We said
Thank you for your request.
We do not hold the information which you have requested. We suggest that you contact the Department for Transport or the Driver and Vehicle Licensing Agency (DVLA) as they may hold the data that you are seeking. They can be contacted at foi-advice-team-dft@dft.gov.uk and foi@dvla.gsi.gov.uk respectively.