One way to look at the rate of immigration is by # per 1,000 inhabitants
The one below is 2017
Australia is 21 but most of the countries above it are small or are ME countries (not really immigrants)
exceptions are Spain, Norway and Canada.
The UK is about 1/2 and the US is 90% of ours but of course has a monster illegal flow.
If we matched Germany at 1.5 we would need to reduce our inflow to 30%.
These are all rough numbers and comments but Australia's inflow per capita is high by any standard.
Column 1 Column 2 Column 3 0 1 British Virgin Islands
16.50 1 2 Luxembourg
15.50 2 3 Qatar
14.60 3 4 Cayman Islands
13.80 4 5 Singapore
13.10 5 6 Bahrain
12.10 6 7 Anguilla
11.70 7 8 South Sudan
10.60 8 9 United Arab Emirates
10.50 9 10 Turks and Caicos Islands
9.50 10 11 Aruba
8.70 11 12 Cyprus
8.70 12 13 Spain
7.80 13 14 San Marino
7.50 14 15 Sint Maarten
6.30 15 16 Isle of Man
6.00 16 17 Norway
5.90 17 18 Canada
5.70 18 19 Monaco
5.70 19 20 Djibouti
5.70 20 21 Australia
5.50 21 22 Belgium
5.40 22 23 Sweden
5.30 23 24 Liechtenstein
5.00 24 25 Austria
4.80 25 26 Switzerland
4.70 26 27 Ireland
4.00 27 28 Iceland
4.00 28 29 United States
3.90 29 30 New Caledonia
3.90 30 31 Italy
3.70 31 32 Macau
3.30 32 33 Jersey
3.20 33 34 Botswana
3.00 34 35 Finland
2.90 35 36 Korea, South
2.50 36 37 United Kingdom
2.50 37 38 Portugal
2.50 38 39 Brunei
2.40
https://en.wikipedia.org/wiki/List_of_countries_by_net_migration_rate#cite_note-cia-1
