In countries with a high vaccination rate, once you get to about 80% coverage it starts to taper off quite noticeably. You never hit 100% due to people who can't or won't take the vaccine.
The first 80% are those that are keen and able for the jab, they get done as soon as they can.The remainder are less interested, live in remote locations or are medically unable.
Tasmania would be waiting a very long time if they want 90%.