If you were ranked first, you would need to get 80-89. However, it depends on how the others are doing. It is not so much your raw assessment mark that matters as your rank. Your raw assessment mark virtually gets thrown out the window, it was only to get your rank. However, it does not sound like you are ranked first, in which case you want all of those ahead of you to be getting in the 90s or high 80s, and you will also have to get high 80s in the exam. This probably isn't likely if you got an assessment mark of 62. There is a big jump.