{
  "report_id": "waitlist-recovery",
  "status": "validated",
  "period": {"start": "2019-01-01", "end": "2026-07-15"},
  "sample": {
    "centers": 2167,
    "joined_classes": 22196853,
    "classes_with_waitlist_and_withdrawal": 3233270,
    "waitlist_entries": 12159475,
    "paired_centers": 1400
  },
  "findings": {
    "median_attendance_per_notified_under_2h_pct": 17.3,
    "median_attendance_per_notified_2_to_24h_pct": 22.4,
    "median_paired_change_pp": -3.0,
    "median_notified_under_2h_pct": 96.1
  },
  "series": {
    "center_balanced_by_latest_withdrawal": [
      {"window": "después del inicio", "centers": 722, "waitlist_entries": 959904, "median_notified_pct": 87.6, "median_reservation_pct": 24.8, "median_attendance_pct": 15.2},
      {"window": "menos de 2 horas", "centers": 1552, "waitlist_entries": 7160984, "median_notified_pct": 96.1, "median_reservation_pct": 22.3, "median_attendance_pct": 14.1},
      {"window": "de 2 a 24 horas", "centers": 1441, "waitlist_entries": 3526519, "median_notified_pct": 80.7, "median_reservation_pct": 22.1, "median_attendance_pct": 16.1},
      {"window": "de 1 a 2 días", "centers": 545, "waitlist_entries": 181038, "median_notified_pct": 52.8, "median_reservation_pct": 17.0, "median_attendance_pct": 12.9},
      {"window": "más de 2 días", "centers": 489, "waitlist_entries": 200317, "median_notified_pct": 38.5, "median_reservation_pct": 10.8, "median_attendance_pct": 7.6}
    ],
    "paired_under_2h_vs_2_to_24h": [
      {"window": "menos de 2 horas", "centers": 1400, "median_attendance_per_notified_pct": 17.3},
      {"window": "de 2 a 24 horas", "centers": 1400, "median_attendance_per_notified_pct": 22.4}
    ]
  },
  "privacy": {"raw_person_identifiers_stored": false, "minimum_waitlist_entries_per_center_and_window": 100},
  "limitations": [
    "El análisis relaciona resultados agregados dentro de una clase; no atribuye una reserva posterior a una baja individual concreta.",
    "La ventana representa la baja más cercana al inicio observada en cada clase.",
    "La comparación es descriptiva y no demuestra que disponer de más tiempo cause la asistencia."
  ]
}