Today, postsecondary educators hold 1.7 million jobs in America. With postsecondary teaching jobs expected to grow by 15 percent by 2018, you might be surprised about who is teaching in college classrooms. As it turns out, vocational and career-related subjects such as health specialties and business have the most instructors, while STEM subjects—such as computer science—lag behind. Even more surprising is how much time full-time professors spend on unpaid or non-teaching related work.