How many people do you think are migrant workers? People who come from an area where that pay is a lot more than they get back home, work for a certain period

How many people do you think are migrant workers? People who come from an area where that pay is a lot more than they get back home, work for a certain period of time before resigning. Then they either go back home or find a better paying job in the new area. Having been a migrant worker myself, I think this is a great way for the mobility of young people, especially when the jobs offer accommodation too.