You should follow the programmed course of study with your training provider. I took 13 months distance learning at about 15hrs/week study and then revision time prior to exams. The course should be 650 hours study time (at least). There is a time limit of 18 months from completion of first series of exams to complete all 14. The amount of time you take should suit your own study timetable and everyone is different so don't worry about the "average person".