Non-scholar / non-selected by management?

Default promotion after fresh AM is 2 years. After that can be up to 4-6 years before you become Deputy Manager.

Some people hit late 40s as Manager (when they have all white hair/balding already). Those few only hit Senior Manager when they are in their late 40s going 50s.

Unless you are chosen by your boss or work in rails with high turnover, you can forget about rising. Your private sector counterparts will overtake you in a few years after graduation.

It's normal.