Data source and references
Visa bulletins from the Department of State
https://travel.state.gov/content/travel/en/legal/visa-law0/visa-bulletin.html Visa bulletins from USCIS
https://www.uscis.gov/visabulletininfo Visa adjustment from USCIS
https://www.uscis.gov/visabulletininfo I-485 inventory data
https://www.uscis.gov/green-card/green-card-through-job/previous-pending-employment-based-i-485-inventory/pending-employment-based-i-485-inventory PERM processing times
https://icert.doleta.gov/ I-130/I-140/I-485 etc processing times
https://egov.uscis.gov/processing-times/