The truck jobs are derived from the CareerBuilder.com API by searching for the keywords "truck driver" in each state at 2:17am each morning and storing the results in a MAFC database. The warehousing jobs follow the same process, but "warehousing" is used as the keyword, and the word "data" is excluded from all results to prevent perhaps the more prevalent type of warehousing job from creeping into the data. The state populations are US Census Bureau estimates from July 2011. The scale used for the "Today" view of the data is dynamically created each day and uses Jenks Natural Breaks, whereas for the "Trend" view the scale simply allocates a color to each state based on whether the change is positive or negative, and a corresponding hue to indicate the magnitude of the change.
