#TfL Freedom of Information release:
Peak Vehicle Requirement Analysis for Bus Route 12 (2015–Present) and Supporting Justifications
The PVR changed as follows:
2015: 34
2018: 33
2019: 24
2022: 15
Current: 15
Set by the bus operating company.
https://tfl.gov.uk/corporate/transparency/freedom-of-information/foi-request-detail?referenceId=FOI-4105-2425