The authority shall prioritize expenditures for treatment provided under RCW
13.40.165. The authority shall provide funds for inpatient and outpatient treatment providers that are the most successful, using the standards developed by the University of Washington under section 27, chapter 338, Laws of 1997. The authority may consider variations between the nature of the programs provided and clients served but must provide funds first for those programs that demonstrate the greatest success in treatment within categories of treatment and the nature of the persons receiving treatment.