Replying to Who is more at risk of brain injury?

This is just out of curiosity and I just want to know everyone's opinion on this topic.

Assuming all are wearing the same helmet, who do you think would be more at risk of a brain injury, and who do you think would be least at risk?

-The novice skier on the bunny slope
-The average "every week/every other week or so" skier
-The advanced skier
-The professional skier

The advanced and professional category would include racers, big mountain, park skiers, mogul skiers, aerialists, etc. etc.

Also, ignore the severity aspect of this hypothetical brain injury.