"What is the percentage of direct workers in an automotive production plant compared to all the employees?"
Details: I am not asking for specific numbers of any production plant. I want to know the general direct worker/employee ratio of a plant. The plants I am interested in are the ones that mass produce for international brands. Including the country the plant is in would also be helpful for categorizing the information.
Example: if there are 1000 employees working usually 700 of them are direct workers etc.
I am looking for estimates backed up with sources or personal experience. Also there may be multiple shifts in a production plant so I am looking for the ratio in a single shift since all the jobs may not get a night shift.
Direct worker means a worker directly working on the production line while employee means all the the people getting paid in that plant.
Edit: Added more information.