Performance by cohort
2 year bands · 6,151 tests
Pass rate climbs 2.8 points across the cohorts — newer Nss examples clear the test more reliably than the early cars.
Pass
85.5%
Fail
10.3%
PRS
3.7%
Avg mileage at test
31,592 mi
Pass
88.3%
Fail
7.8%
PRS
3.4%
Avg mileage at test
25,132 mi
Cohort = vehicle's first-registration year band. Same model, different generations of build.