The first-time pass rate is the share of first inspection attempts that ended in a pass (a no defects or minor defects verdict). Re-inspections and document-issuing records are excluded.
What sample size is needed before a figure is published?
A model-year page is indexed from 100 inspections, a model page from 500, and an age-band cell is shown from 30. Smaller samples are marked as indicative. Every figure comes with n and a confidence interval.
Can models of different ages be compared?
Not directly – older cars pass less often. Compare within the same age band: the reliability rankings work exactly that way, and every model-year page, for example of the Volkswagen Golf, shows the M1 average at the same age.
Does it describe a particular car?
No. It is a statistic about a model and year of manufacture. A specific car's history needs its own check – start with is the mileage normal?