Complex sentence: In 2004, with 13 students, 4 part-time teachers were hired to develop and teach online courses; in 2005, there were 4 teachers, all full time, and 46 students.
Split into simpler sentences: In 2004, with 13 students, 4 part-time teachers were hired to develop and teach online courses. In 2005, there were 4 teachers, all full time, and 46 students.