# Dataset splits — hash-pinned 2026-06-06

Built by `scripts/build_canonical.py` from `data/sir_raw.parquet`.

- Seed: `20260606`
- Stratified by: `naics_subsector` (first 4 digits of Primary NAICS)
- Train ratio: 70% | Dev ratio: 15% | Test: remainder

## Counts
- total: 103,750
- train: 72,467
- dev:   15,410
- test:  15,873

## Test split top subsectors
2381=686, 2382=549, 2362=383, 2131=380, 6221=362, 4451=332, 4931=329, 3116=323

## Test split SHA-256
`c9490ed3177e63c6128f9e75e91d836b02ce09e464ea8e40f2717f1a15a0148a`

The test split MUST NOT be re-shuffled or re-split. If `SPLITS.md` is
ever regenerated, verify the SHA-256 above is unchanged.