Where are you getting that 90% number from? That doesn't match with any source I'm familiar with. For example, the 2023 statewide homeless study from UCSF (https://homelessness.ucsf.edu/sites/default/files/2023-06/CA...) reported these numbers: "We describe current regular use of cocaine, amphetamines, and non-prescribed opioids as use three times a week or more. By this definition, one third (35%) of participants reported currently using cocaine, amphetamines, or non-prescription opioids regularly (Figure 31). Thirty-one percent of participants report current regular use of methamphetamines; 3% cocaine, and 11% non-prescribed opioids. In the prior six months, 13% of all participants report using injection drugs."