There are 167,000 workers on 457 visas in Australia right now. I have seen statistics that show two out of three skilled Australian jobs are filled by foreign workers, jobs that should be filled by training Australians.
While 457 visas are a rort this stat doesn't pass the sniff test. Are you saying 2/3rds of skilled jobs in Australia = 167,000? That means that there is only 250,500 skilled jobs in all of Australia, with a population of over 20 million people?