In the 2004 Survey of Inmates in State and Federal Correctional Facilities, 32% of state prisoners and 26% of federal prisoners said they had committed their current offense while under the influence of drugs. Among state prisoners, drug offenders (44%) and property offenders (39%) reported the highest incidence of drug use at the time of the offense. Among federal prisoners, drug offenders (32%) and violent offenders (24%) were the most likely to report drug use at the time of their crimes. About 74% of state prisoners who had a mental health problem and 56% of those without were dependent on or abused alcohol or drugs. By specific type of substance, inmates who had a mental health problem had higher rates of dependence or abuse of drugs than alcohol. Among state prisoners who had a mental health problem, 62% were dependent on or abused drugs and 51% alcohol. Over a third (37%) of state prisoners who had a mental health problem said they had used drugs at the time of the offense, compared to over a quarter (26%) of state prisoners without a mental problem" Can you describe the relationship between mental illness and substance abuse based on these statistics?