29.2% (5) of medical schools in Australia are 6 years.
27.2% (7) are 5 years.
43.6% (11) are 4 years.
Well sort of -- schools with multiple programs are listed multiple times (there aren't 23 med schools but 19 if counting Notre Dame appropriately as two), and I think your percentages are referring to student numbers not schools. More than 50% of students are grad entry, but that percentage continues to grow as some undergrad programs are phased out (as their remaining cohorts graduate) and the newer grad programs add cohorts.
It is of note that the only new undergrad school in the past 10 years was UWS, while there have been at least 6 new grad programs. Melbourne undergrad's last intake was 2008, and even its 5year grad program has stopped intakes, leaving only its 4year grad program taking new students. Bond is a 5yr program that's now mostly undergrad but still ~20% grad, and UWA has both a (new) 5 year grad program and its old 6 year undergrad program.
In terms of current intakes, I *think* the breakdown is:
9 schools have significant undergrad intakes:
Adelaide
Bond
JCU
Monash
Newcastle
UNSW
UTas
UWA
UWS
13 schools have significant grad intakes:
ANU
Bond
Deakin
Flinders
Griffith
Melbourne
Monash
Notre Dame (Fremantle)
Notre Dame (Sydney)
UQ
USyd
UWA
Wollongong
(3 schools [UWA, Bond, Monash] have significant intakes for both)
At any rate, the balance of power in AMSA first shifted to the grad programs in 2008.