21 Association of Research Libraries Research Library Issues 295 — 2018 an opportunity to address new needs that can help the library adapt to changes on campus and the broader external environment. New hires are the best indication we have as to current demand for various kinds of professional expertise. In 2015, the ARL Salary Survey included 21 job categories, but hiring is by no means evenly distributed among those categories. Figure 5 compares the six job categories that had the most new hires in 1986 and 2015. Though the top six categories were different in 1986 and 2015, in both years employees in these categories accounted for over 70% of all new hires. Figure 5 illustrates that tracking job categories across years in the ARL demographic data is inherently messy, as these categories have evolved rapidly in an effort to keep pace with emerging staffing needs. For that matter, most of the changes in job categories have been driven by the explosive growth in nontraditional library professional jobs. I define nontraditional jobs to be those for which the primary expertise requirement lies in fields beyond librarianship, for example computing, financial, legal, human resources, and so on. Figure 5