Chart 1: Number of people in detention and average length of detention (during month of June 2013–2023)22 800 742 9256 720 10000 711 673 640 9000 8000 551 560 467 459 480 7000 485 6000 436 405 400 350 5000 320 3624 4000 3000 240 160 2013 81 1577 1347 1262 1352 1523 1492 1398 80 0 2013 2014 2015 2016 2017 2018 Average length of time in detention 2.3 Reasons for detention Historically, asylum seekers who arrived by boat have typically comprised the majority of people in closed immigration detention. Since the beginning of 2014, this group has progressively comprised a smaller proportion of the detention population. At the same time, the number of people in detention due to cancellation of their visas has increased. This increase has been largely due to legislative amendments that broadened the scope of s 501 of the Migration Act.23 Section 501 allows the Minister or their delegate to refuse or cancel a visa on the basis that a person does not pass the ‘character test’. The legislative amendments introduced mandatory visa cancellations for people who have a ‘substantial criminal record’ or have committed 2019 2020 2021 2022 2000 1114 2023 1000 0 Number of people in detention a sexually based offence involving a child, and are serving a full-time term of imprisonment for an offence against an Australian law.24 The Department has reported that from the time this legislative amendment came into effect on 11 December 2014 until 31 March 2016, there had been 1152 mandatory cancellations under s 501(3A).25 The Commonwealth Ombudsman commented in 2016 that it was ‘apparent… that the number of persons subject to cancellation under s 501 was underestimated prior to the passage of the legislation’.26 Throughout 2023, people detained due to the cancellation of their visa under s 501 consistently comprised near to, and over, 60% of the overall detention population.27 Yongah Hill Immigration Detention Centre Inspection Report • 2024 • 13