Definition — Number of people aged 20-64 per person aged 65 or over: Insee population estimates (provisional for the latest years), then the central demographic projection used by the COR (June 2026).

• Projections: reference scenario of the COR (Conseil d’orientation des retraites), annual report of June 2026 — central Insee demographic assumptions (fertility 1.45 from 2028, net migration +150,000 a year), hourly labour productivity +0.7 % a year, unemployment 7 % from 2040. It is a scenario, not a forecast: it is sensitive to the productivity, unemployment and net-migration assumptions. The headline is always the last observed year, never a projection.
• Insee population estimates are provisional for the latest years: 2024 to 2026 (population on 1 January) are shown as estimates (dashed), the headline is the last observed year.
• Licence : Licence Ouverte / Etalab 2.0 — COR (Insee, Drees, CCSS sources)