The Visibility Index condenses every tracked prompt×engine into one 0–100 number, so you watch one line instead of a hundred rows.
How it is scored
Each slot scores by outcome: cited at #1 near 100, decaying with rank; a mention partial; absent zero. The Index averages your active slots, so adding hard new prompts you do not yet win will correctly pull it down until you earn those citations.
Deltas and year-over-year
Each range compares now to the start of that window; the green/red badge is the change. With a year of history a YoY badge appears too. A dash means not enough history in that window yet.
Use 30d to react to recent change, and 12 months to prove the long-term trend to a client or boss.