The NSW Education department has released its latest "disability strategy" (download here).
In relation to autistic students, it says:
autistic students are 33% of "students supported by funded programs distributed by disability type 2017" in NSW (students with intellectual disability make up 40%).
"From 2013-17, enrolments of students with autism increased by ~14.5% per year" according to the Education Department's own data ... at this rate, the number of autistic students doubles every 5 years.
"In 2016, The NSW Auditor-General reported that teachers felt they lacked expertise and wanted greater support to help manage student behaviour, and to better support students with autism and mental health needs".
the NSW Education Department will "Invest in research to better understand the prevalence of autism and mental health in our schools".