Rob1975, do you keep your seatbelt loosely fastened even when you visit the toilet?
The statistics don't always lie!
If Rob1975 keeps his seatbelt fastened throughout the flight, save for that trip to the cubicle he has a statistically insignificant chance of being injured by turbulence.
The cabin crew on the other, are generally standing, unrestrained and often pushing a heavy trolley. This fact coupled with their greater proximity to other hazards such as ovens, hot water etc. make them far more likey to be injured in that low probability (but still possible) CAT event.
Rob is right. Stay buckled, not too loosely if you can.