European consumption rooms cater more so to users older than 30 years, mainly with problematic heroin and cocaine habits. Various studies have documented an ageing population of clients over time. Whereas in 1990, in one study, 50% of clients were 25 years or younger, by 2001 the percentage was 15%. Clients across European consumption rooms are characterized by heavy injecting drug use, a continuous use of illicit drugs and deriving from a poorer demographic. German studies found that between 19% and 27% of clients were from unstable accommodation. In the injecting rooms near Madrid, 42% of the marginalized target group were homeless, while the number was 60% for the Can Tunis area of Barcelona. In a German study 15% of clients had never accessed addiction treatment of any kind.