a "labour job" is in fact a rather variable / shifty notion.
In UK a "labour job" most literally would be a job a "labourer" (no qualifications required) on a building site, not exactly the same as "Examples of 'labour jobs' are : oil field worker, fruit picker, cleaning staff."
in you look at the International Standard Classification of Occupations
https://en.wikipedia.org/wiki/International_Standard_Classif... you will find "managers" and "professionals", but no trace of any "labour jobs" NOR
"intermediate job'" (e.g. long-haul truck driver). (NEVER heard to that category, BTW! - what's that? "intermediary
on what kind of scale? )
What exactly are supposed to be "labour jobs"
in this survey depends on the purpose of survey, who or what is being surveyed, and how other categories have been defined. And of the country involved. Canada? USA?