The Australian Treasury reported that border policies cost $4 billion in 2016–17. The Australian Financial Review reported that this figure comprised $1.57 billion for detention within Australia, $1.08 billion for offshore centres in Nauru and Papua New Guinea, and $1.06bn on border enforcement. As a result, the yearly cost of holding one person in onshore detention in 2017-18 was $346,178.
At end 2017, according to the new home affairs department, there were 1301 people in onshore detention facilities, including 988 in detention on the mainland and 313 on Christmas Island. There are a further 339 people on Nauru and 801 people in Papua New Guinea (of which 616 have been recognised as refugees).
In 2017, 171,802 people arrived in Europe by sea, around half the number of 2016. The International Organization for Migration reported 3116 people dead or missing in the Mediterranean, the fourth consecutive year of over three thousand deaths.