Yerevan's chronic problems

A 100-point index — the geometric mean of four properties of the problem itself: harm (1–5) and reach (1–5), how serious the consequences are and how many people they touch; trajectory, whether it's worsening or easing; and entrenchment, how many years it has dragged on. The geometric mean stops any single strong axis from carrying the rest. How much we've documented is not part of the score — it's shown separately, as evidence strength.