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".