Jennifer, a college student in Atlanta, Georgia, contacted the Delta Airlines headquarters to ask if she could interview a pilot to help her with her upcoming speech on the commercial airline pilot shortage the world will face in the next $15$ years. To her surprise, the chief pilot at Delta Airlines called her and spent an hour talking to her about why he and many other pilots are worried about the future of commercial aviation due to the mandatory retirement age and the high costs associated with flight school. What type of information did the chief pilot give Jennifer?