This report is a little frustration specifically because it lacks some of the most specific stuff: Statistics. Yet the case study details in it are more than compelling.
This is a just-out report called (in over-long title) "A Survey of Human Trafficking in the Spokane Region: Conducted by the Inland Northwest Task Force on Human Trafficking," prepared by Debbie R. DuPey for the Western Regional Institute for Community Oriented Public Safety at Washington State University-Spokane.
How widespread is this activity? What are the numbers that could give some perspective to it? Those aren't here, as the report's introduction says: "The interview instrument and methodology were not quantitative in nature, and therefore a formal numerical estimate of trafficking victims in the Spokane region is not included in this report."
Still: "The data obtained in the survey is subjective and based on the interpretation of the interviewees, reflecting how they extract meaning from the definition posed and apply it to their interactions with the individuals they serve. However, all of the interviewees were professionals trained in working with vulnerable populations. It is assumed that their subjective interpretations have merit for the purposes of this survey."
And there is enough to put some parameters on the problem. It is broken down by type (gang-related, prostitution, "mail-order brides" and so on) and these are described with some detail.
Till more comes in, this is a report of value.