How much of my GCP spend has no labels?

SELECT
  project.id                                                 AS project_id,
  ROUND(SUM(cost), 2)                                        AS total_cost,
  ROUND(SUM(IF(ARRAY_LENGTH(labels) = 0, cost, 0)), 2)       AS unlabelled_cost,
  ROUND(SAFE_DIVIDE(
    SUM(IF(ARRAY_LENGTH(labels) = 0, cost, 0)),
    SUM(cost)), 3)                                           AS unlabelled_fraction
FROM `PROJECT.DATASET.gcp_billing_export_v1_XXXXXX_XXXXXX_XXXXXX`
WHERE _PARTITIONTIME >= TIMESTAMP_SUB(CURRENT_TIMESTAMP(), INTERVAL 35 DAY)
  AND cost > 0
GROUP BY project_id
ORDER BY unlabelled_cost DESC;