Not parent, but Oman Air Paris to Muscat leg has been ~50% full at the most the last 3 times I took it. They're a top notch airline, flying Boeing 787, and their Muscat to final destination leg has always been full (same as the Muscat to Paris return flight), so I can't figure out why other than "I've been lucky" when the likes of Emirates/Etihad/Qatar Airways/... are full as can be.
Picture from my mid-May flight after closed doors: http://imgur.com/a/8ikMP