The figures above are for unique arrests in Vigo County. Arrests may have multiple substance-related charges (for example someone may receive two charges, one for possession of methamphetamine and another for possession of marijuana in the same arrest) but it is still only counted for that arrest once in the graphic above.
An arrest is counted as a “substance-use related” arrest if the charges include any form of substance listed in the charges (methamphetamine, marijuana, alcohol, controlled substance, etc.), and things like driving while intoxicated and public intoxication are also included in these figures.