# Provenance — fig2-formation-decline

**Chart type:** two-point slopegraph / line (single series, year columns 2020/21 → 2024/25, shared count axis).
**Why this, not that:** the claim is a single-series decline between two verified endpoints. A slope line shows the fall (magnitude + direction) directly and honestly. A bar pair would work but the slope reads the trajectory ("continuous decline") more immediately; the −30% is annotated so the reader does not have to compute it. Only two points are plotted because only two per-year values are verified.

**Honesty notes (load-bearing):**
- HESA academic-year founding figures.
- Only the two **verified endpoints** are plotted: 202 (2020/21) and 141 (2024/25). The source states the intervening years (2021/22–2023/24) fall continuously but does **not** give their per-year values, so no intermediate points are plotted — the line spans endpoint-to-endpoint and "continuous four-year decline" is carried as a **text annotation**, not fabricated points.
- **−30% is derived**, not source-stated: (202 − 141) / 202 = 30.2%, shown as −30%.
- Count axis is zero-based (0–250) — no truncation exaggerating the drop.

| id | series | period | value | source (publisher) | url | anchor | quote |
|---|---|---|---|---|---|---|---|
| formation-2020 | formation | 2020/21 | 202 | HESA (HE-BCI), via Times Higher Education | https://www.timeshighereducation.com/news/slowdown-university-spin-out-creation-wake-call-uk | sources.md:10 | 202 spinouts (2020/21) |
| formation-2024 | formation | 2024/25 | 141 (primary) | HESA (HE-BCI), via Times Higher Education | https://www.timeshighereducation.com/news/slowdown-university-spin-out-creation-wake-call-uk | sources.md:10 | 141 (2024/25) |

**Source:** HESA (HE-BCI survey), as reported by Times Higher Education, "Slowdown in university spin-out creation a 'wake-up call' for UK" (30 April 2026) — https://www.timeshighereducation.com/news/slowdown-university-spin-out-creation-wake-call-uk

**Encoding decisions:** ink ground `#0A1428`; bone `#F4F1EA` for the 2020/21 origin point + shared context label; exactly one ember `#E85D2F` on the 2024/25 endpoint (primary/worry), the connecting line, and the −30% figure + its faint range-frame rule; Inter for labels, JetBrains Mono for values; direct-labelled (no legend); zero-based count axis (no truncation). Layout is consistent with fig1: a **top-left title + subtitle**, the value label above / year caption below each point, and the −30% figure placed in the **right clear space** beside the 2024/25 endpoint.

**Kill-list overrides:** none.

**Checklist (tufte/checklist.md, 12-item):** PASS. Verified by headless-Chromium render on the ink panel + read-back (squint test): the decline and the −30% read in one glance, one ember accent, no label collisions, honest zero-based axis, no chartjunk. role="img" + aria-label present.

**Generator:** hand-authored flat inline SVG (matches the shipped figure convention in this repo). Geometry computed to a zero-based value→pixel map. No separate generator script.