Are my BigQuery queries queueing for slots?

-- JOBS_TIMELINE reports slot usage per second-level period, so it shows
-- true concurrency rather than a per-job total smeared over its runtime.
-- A script's parent job repeats its children's slot use, so it is left out.
-- The view is partitioned by job_creation_time, not period_start: the
-- job_creation_time filter is what keeps this from reading 180 days.
SELECT
  TIMESTAMP_TRUNC(period_start, HOUR)                        AS hour,
  COUNT(DISTINCT job_id)                                     AS concurrent_jobs,
  ROUND(SUM(period_slot_ms) / 1000 / 3600, 2)                AS slot_hours,
  ROUND(SUM(period_slot_ms) / 3600000, 1)                    AS avg_slots_in_hour,
  MAX(period_slot_ms)                                        AS peak_period_slot_ms
FROM `region-us`.INFORMATION_SCHEMA.JOBS_TIMELINE_BY_PROJECT
WHERE period_start >= TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 7 DAY)
  AND job_creation_time >= TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 8 DAY)
  AND job_type = 'QUERY'
  AND (statement_type != 'SCRIPT' OR statement_type IS NULL)
GROUP BY hour
ORDER BY avg_slots_in_hour DESC
LIMIT 100;