Am I interpreting the data correctly in that, whatever protective effect was found on Taxi drivers and Ambulance drivers, was actually aggravated on Ship Captai

Am I interpreting the data correctly in that, whatever protective effect was found on Taxi drivers and Ambulance drivers, was actually aggravated on Ship Captains and Airline Pilots? My immediate thought went to the negative effect of sleep quality and work schedules, but I would expect the same sleep strain/stress for Ambulance drivers. A lot going on epidemiology wise but interesting study nevertheless.