If you like to dig deep into data and reports, here's the one for you.
The 2022 Caseload and Cost Report for DDA Services has all the info you need for the WHO's getting services or not, WHAT services were accessed, WHERE people live and WHERE services are, and much more.
Check it out here
https://www.dshs.wa.gov/sites/default/files/DDA/dda/documents/2022DSHSDDACaseloadandCostReport.pdf